Which of these terms is a common parlance used to mean by 'injection'?

Correct Answer: C

Rationale: In everyday language, injection' broadly refers to delivering a drug via a needle, encompassing various routes. 'Parenteral,' is correct because it's the umbrella term for all injections (bypassing the gut), including intramuscular, subcutaneous, and intravenous, as per pharmacology texts (e.g., Katzung). 'Intramuscular,' and 'Intravenous,' are specific routes, not the general term. 'Subcutaneous,' is another specific method. Parenteral's broad usage in healthcare—covering any needle-based administration—makes it the common parlance for injection,' distinguishing C as the accurate answer over narrower options.

Correct Answer: B

Rationale: A pilot study tests feasibility before a full research project. 'A small scale study conducted in advance...,' is correct, describing its role in refining methods and logistics, per research methodology (e.g., Polit & Beck). 'A scientific study carried out on pilots,' misinterprets pilot.' 'The first and most important step,' overstates its priority; it's optional. 'A study conducted simultaneously...,' is incorrect; pilots precede, not parallel, main studies. B's focus on pre-testing feasibility matches standard practice, making it the accurate answer.

Correct Answer: A

Rationale: Nominal variables are categorical without order. 'Ethnicity,' is correct, as it labels groups (e.g., Asian, Caucasian) without ranking, per statistical classification (e.g., Agresti). 'Socio-economic status,' is ordinal, with levels (e.g., low, high). 'Class positions,' is ordinal, implying rank. 'Weight,' is ratio, measurable with a zero. Ethnicity's lack of numerical or hierarchical properties makes A the precise nominal answer.

Correct Answer: C

Rationale: Cardiac output (CO) is heart rate (HR) times stroke volume (SV). Given HR = 84 bpm and SV = 60 ml (0.06 L), CO = 84 × 0.06 = 5.04 L/min, approximated as 5 L/min. '5 L/min,' is correct, per physiology (e.g., Guyton). The question's exercise scenario (13 L/min) is post-exercise, but initial CO aligns with resting values. Choices A, B, and D miscalculate. C's accuracy makes it the answer.

Correct Answer: D

Rationale: Antigen-presenting cells (APCs) process and display antigens to T-cells, initiating adaptive immunity. 'Natural killer cells,' is correct as the exception, per immunology references like Abbas' Basic Immunology, as NK cells target infected cells directly, not presenting antigens. 'Macrophages,' engulf pathogens and present antigens via MHC. 'Dendritic cells,' are potent APCs, activating naive T-cells. 'B-Lymphocytes,' present antigens to helper T-cells for antibody production. NK cells' innate cytotoxic role, lacking MHC presentation, distinguishes D as the accurate answer, separate from APC functions.