Question

mental age is an age by which ________. one can perform certain skills one can complete age - related problems one has acquired certain skills one shows signs of graduating from high school

Explanation:

Mental age refers to the level of cognitive development, measured by the age - related skills one has acquired. The option "one has acquired certain skills" aligns with the definition of mental age. "Perform certain skills" is not as accurate as "acquired", "complete age - related problems" is too narrow, and "signs of graduating from high school" is not related to the concept of mental age.

Answer:

C. one has acquired certain skills (assuming the options are labeled A, B, C, D with A: one can perform certain skills, B: one can complete age - related problems, C: one has acquired certain skills, D: one shows signs of graduating from high school)