Which of the following statements about heredity and intelligence is true?

a. Similarities in intelligence between identical twins who were separated at birth and raised in different houses must be due to heredity.

b. Differences in intelligence between identical twins must be due to differences in their environments.

c. If identical twins are separated at birth and raised in different homes, yet still have similar intelligence scores, the similarity in their scores must be due to hereditary influences.

d. Prenatal influences have little, if any, influence on intelligence and need not be taken into account when studying environmental influences.

b. Differences in intelligence between identical twins must be due to differences in their environments.

Explanation:

Almost all psychologists agree that heredity and environment are important in determining each individual's level of intelligence. Disagreements arise as to the relative weight of each of the factors. However, psychologists today tend to be more interested in how the two factors interact than in which one matters most.

According to this concept, it was established that in identical twins, heredity would influence the same level of intelligence, but different environments would influence different intelligences, that is, differences in intelligence between identical twins must be due to differences in their environments.

I think option C is correct by my opinion.