Final answer:
Option D). Facial hair growth is a primary sex characteristic that might develop soon for Samuel during puberty.
Step-by-step explanation:
Males go through a variety of physical changes during puberty. Facial hair growth is one of the main sex traits that Samuel may soon acquire. This is because the body produces more testosterone, which promotes the growth of all hair, including facial hair. Boys may also experience other secondary sex traits during puberty, such as a deeper voice, pubic and armpit hair growth, and testicular and penile growth. Hence, Option D) is the correct answer.