Answer: Blood transfusion > needle sharing > mother to child > sexual intercourse.
- A Blood transfusion > sexual intercourse > mother to child > needle sharing
- B Sexual intercourse > blood transfusion > needle sharing > mother to child
- C Blood transfusion > needle sharing > mother to child > sexual intercourse
- D Mother to child > blood transfusion > sexual intercourse > needle sharing
Correct answer: C. Blood transfusion > needle sharing > mother to child > sexual intercourse
Explanation: HIV transmission probability per exposure: blood transfusion (90-95%) is highest, followed by needle sharing (0.67%), then mother-to-child transmission (15-45%), and sexual intercourse (0.1-1% depending on type).
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.