Answer: Chemically immobilising or killing sperm on contact.
- A Forming a physical barrier directly over the narrow cervical opening
- B Chemically immobilising or killing sperm on contact
- C Altering cervical mucus consistency mainly to trap and slow down sperm
- D Lowering testosterone levels in males gradually over an extended period
Correct answer: B. Chemically immobilising or killing sperm on contact
Explanation: Spermicides contain chemicals like nonoxynol-9 that chemically immobilise or kill sperm by disrupting their cell membranes. They are most effective when used in combination with barrier methods like diaphragms.
Contraceptive methods span a spectrum from temporary/natural to permanent/surgical; condoms stand out as the only method offering STI protection alongside contraception.
Concept context
Understand reproductive health, family planning, contraception methods, STIs, population control, and assisted reproductive technologies.