The approximate length of the male urethra is

Correct Answer: B

Rationale: The male urethra averages 20 cm, spanning prostatic, membranous, and spongy parts. '20 cm,' is correct, per anatomy texts like Netter, varying slightly (18-22 cm). '15 cm,' is short. '25 cm,' and '30 cm,' exceed typical length. The 20 cm standard reflects its path from bladder to external meatus, making B the accurate answer.

Correct Answer: C

Rationale: Long bones are longer than wide, in limbs. 'Carpals,' is correct as the exception, short bones in the wrist, per anatomy (e.g., Tortora). 'Humerus,' 'Femur,' and 'Tibia,' are long bones. Carpals' compact shape makes C the precise answer.

Correct Answer: B

Rationale: The skin, covering the body, is the largest organ by surface area and weight (about 15% of body mass). 'Skin,' is correct, per anatomy (e.g., Tortora). 'Liver,' is largest internal. 'Heart,' and 'Lungs,' are smaller. Skin's expanse makes B the precise answer.

Correct Answer: D

Rationale: Sterilization eliminates all microbes. 'Incubation,' is correct as the exception, growing organisms, per microbiology (e.g., Prescott). 'Autoclaving,' uses steam. 'Dry heat,' uses ovens. 'Filtration,' removes microbes. Incubation's growth purpose makes D the accurate answer.

Correct Answer: D

Rationale: Zoonotic diseases transfer from animals to humans. 'Influenza,' is correct as the exception, primarily human-to-human, though some strains (e.g., avian) are zoonotic, per epidemiology (e.g., Morens). 'Rabies,' 'Anthrax,' and 'Tuberculosis,' are zoonotic. Influenza's typical transmission makes D the accurate answer.