Correct Answer: B

Rationale: The correct answer is the third month of pregnancy (choice B). During the third month of pregnancy, which is around 9-12 weeks, a fetal heartbeat can typically be heard using a stethoscope. This is an exciting milestone for expectant parents as it provides reassurance about the baby's well-being. Choices A, C, and D are incorrect because by the fourth week of pregnancy, the fetal heartbeat is not usually detectable with a stethoscope. The end of the second trimester and the beginning of the third trimester are too late in the pregnancy timeline for this milestone.

Correct Answer: B

Rationale: A small-for-date baby, also known as a small-for-gestational-age (SGA) baby, is a baby who is born below their expected weight considering the length of the pregnancy. This can be due to various factors including issues with growth restriction in the womb. Being small-for-date is different from being preterm (born prematurely) and does not necessarily mean that the baby was born early. Choice A is incorrect because being small-for-date does not specifically indicate being born several weeks or more before the due date. Choice C is incorrect because being small-for-date does not guarantee fewer problems than a preterm infant, as each baby's health outcomes can vary. Choice D is incorrect because while small-for-date babies may have initial difficulties, it does not guarantee that these issues will be outgrown by the preschool years.

Correct Answer: C

Rationale: The first successful intelligence test, the Binet-Simon Scale, was originally developed to identify children with learning problems who required special educational interventions. Choice A is incorrect because measuring individual differences in IQ was not the primary purpose of the test. Choice B is incorrect because documenting age-related improvements in children's intellectual functioning was not the main goal of the test. Choice D is incorrect because comparing the scores of people based on gender, ethnicity, and birth order was not the intended use of the intelligence test.

Correct Answer: B

Rationale: During the first week of pregnancy, the zygote (fertilized egg) undergoes rapid cell divisions and forms a blastocyst. This is a crucial stage where the cells differentiate and specialize, setting the foundation for the development of the embryo. It is during this time that the zygote implants itself into the uterine wall, initiating the process of pregnancy. Choices A, C, and D are incorrect because during the first week of pregnancy, the focus is on the initial development and multiplication of the zygote, not on the development of heart muscles, a primitive brain and spinal cord, or the embryo's ability to move.

Correct Answer: B

Rationale: A theory of development describes, explains, and predicts behavior. It provides a framework for understanding how individuals grow and change over time. The purpose of a theory is not to illustrate ultimate truth or explain all aspects of human growth, but rather to help researchers and practitioners make sense of and predict human behavior. Theories are expected to be tested and refined through scientific verification. Choice A is incorrect because theories do not necessarily illustrate ultimate truth. Choice C is incorrect as theories focus on behavior and development, not all aspects of human growth. Choice D is incorrect because scientific verification is essential for theories to be valid and reliable.