Which sequence best describes the basic SMR timeline of male puberty?

• A. Pubarche → Spermarche → Testicular enlargement → Growth spurt (SMR 3-4) → Spermarche
• B. Testicular enlargement → Pubarche → Growth spurt (SMR 3-4) → Spermarche → Masculinization
• C. Spermarche → Testicular enlargement → Pubarche → Masculinization
• D. Testicular enlargement → Growth spurt → Pubarche → Spermarche

Answer: (B)

The sequence reflects the typical order of puberty milestones in boys as described by Tanner staging. The first signal of puberty is testicular enlargement, which marks the onset of puberty. Pubarche, the appearance of public hair, follows as androgen effects develop. The growth spurt usually occurs midpuberty, around SMR 3-4. Spermarche—the first ejaculation—occurs after the growth spurt as reproductive maturity advances. Masculinization, including deepening voice and facial/body hair, appears later as full secondary sexual characteristics develop. This progression matches the described sequence: testicular enlargement → pubarche → growth spurt (SMR 3-4) → spermarche → masculinization. The other options mix the order (for example, placing spermarche before testicular enlargement, or pushing the growth spurt ahead of pubarche), which is why they’re not correct.