Question

girls are usually completely physically mature by the time they are ____ years old.
a. 15 to 17
b. 17 to 19
c. 12 to 15
d. 18 to 21
please select the best answer from the choices provided.
○ a
○ b
○ c
○ d

Explanation:

This question is about the physical maturity of girls, which falls under the subfield of Biology (a part of Natural Science) or potentially Psychology/Health in Social Science, but more closely related to biological development. From developmental biology and human growth knowledge, girls typically complete physical maturity (like skeletal and reproductive system development) around 15 - 17 years? Wait, no, correction: Actually, the typical range for girls to be completely physically mature (including full growth, reproductive system maturity) is often around 15 to 17? Wait, no, let's recall: Puberty in girls starts earlier, and physical maturity (like reaching full height, skeletal maturity) is often completed by around 15 - 17, but some sources say up to 19? Wait, no, the options: Option A is 15 to 17, B 17 to 19, C 12 to 15 (too early, as 12 - 15 is still puberty), D 18 to 21 (too late for most). Wait, actually, the correct range for girls' physical maturity (completion of growth, secondary sexual characteristics, reproductive system) is often considered 15 to 17? Wait, no, maybe I got it wrong. Wait, let's think again. The average age for girls to stop growing (physical maturity) is around 15 - 17, while boys are later. So among the options, A (15 to 17) is a common range. Wait, but some sources say 17 - 19? No, 12 - 15 is puberty onset, 15 - 17 is completion? Wait, maybe the answer is A? Wait, no, let's check the options again. The question is "Girls are usually completely physically mature by the time they are ___ years old." The options: A.15 to 17, B.17 to 19, C.12 to 15, D.18 to 21. So C is too early (12 - 15 is when puberty is happening, not completed), D is too late (21 is beyond typical), B is 17 - 19, A is 15 - 17. Actually, the correct answer is A? Wait, no, maybe I'm mixing up. Wait, the physical maturity (like skeletal age, reproductive maturity) for girls: most girls complete physical growth (height) by around 15 - 17, with some variation. So the best answer here is A.15 to 17.

Answer:

A. 15 to 17