Correct Answer: A

Rationale: Amino acids are the correct answer because they are the building blocks of proteins that the body absorbs after digestion. Pepsin, choice B, is incorrect as it is an enzyme that aids in the digestion of proteins, not the absorbable unit of them. Choices C and D, glucose and sucrose, are wrong because they are types of sugars, not proteins.

Correct Answer: B

Rationale: The first step in the scientific method is to make an observation and ask a question. This is because the scientific method is a systematic process of investigation that begins with observing a phenomenon or asking a question about it. This is followed by formulating a hypothesis (Choice C), designing and conducting an experiment to test the hypothesis (Choice A), and analyzing the results to reach a consensus or conclusion (Choice D). Therefore, choices A, C, and D are incorrect as they represent steps that occur after the initial observation and question.

Correct Answer: B

Rationale: The correct answer is B, Altered taste sensation. The use of antibiotics is known to cause changes in taste sensation as a side effect, especially when used to treat H. pylori infections. Hemoptysis (Choice A) refers to coughing up blood, and while it can be a symptom of various conditions, it is not typically associated with the use of antibiotics. Flatulence (Choice C) and bloody stools (Choice D) can also occur as gastrointestinal complications, but they are not the most likely side effect when treating H. pylori with antibiotics. Therefore, choices A, C, and D are incorrect.

Correct Answer: D

Rationale: The correct answer is phosphorus. Retention of phosphorus in patients with Chronic Kidney Disease (CKD) contributes to the development of bone disorders, including osteodystrophy, because it disrupts the balance of calcium and phosphorus in the body. This imbalance leads to a variety of bone diseases. The other options - iron, sodium, and potassium - while important in the overall metabolic function, are not directly linked to the development of bone diseases in CKD patients due to retention.

Correct Answer: D

Rationale: Smoking is a major risk factor for atherosclerosis. It significantly contributes to the buildup of plaque in the arteries and thereby increases the risk of cardiovascular diseases. On the other hand, exercise is generally beneficial for cardiovascular health and is not a risk factor for atherosclerosis. Excessive sun exposure and insufficient vaccinations have no established links to atherosclerosis, making them incorrect options for this question.