Reasons for premedication include one of the following:

Correct Answer: B

Rationale: Premedication before anesthesia aims to optimize patient condition. 'To attenuate vagal responses,' is correct because drugs like atropine reduce vagal-induced bradycardia or secretions, per anesthesiology standards (e.g., Stoelting's Pharmacology). 'To increase volume of gastric content,' is false; it's minimized to prevent aspiration. 'To stimulate secretions,' is incorrect; drying secretions is preferred. 'To increase fear and anxiety,' opposes premedication's anxiolytic goal (e.g., midazolam). Attenuating vagal responses enhances safety, making B 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.

Correct Answer: B

Rationale: The uterine (fallopian) tube is about 10 cm long, extending from ovary to uterus. '10 cm,' is correct, per anatomy texts like Netter's Atlas, varying slightly (7-12 cm) but typically cited as 10 cm. '5 cm,' is too short. '15 cm,' and '20 cm,' exceed average length. The tube's role in ovum transport supports B's accuracy, reflecting standard anatomical measurements.