Final answer:
Boys are more likely to develop acne than girls due to higher levels of testosterone, which leads to an overproduction of sebum and clogged pores.
Step-by-step explanation:
Boys develop acne more than girls because of greater levels of testosterone. Testosterone is a type of androgen, which are hormones that contribute to the maturation and functioning of the skin's oil glands, known as sebaceous glands.
During puberty, increased testosterone levels can lead to an overproduction of sebum, which, in combination with dead skin cells and dirt, can clog pores and provide a breeding ground for propionibacterium, leading to acne. The correct answer to why boys may develop more acne is A. Testosterone.