The single, general factor for mental ability that is assumed to underlie intelligence

The answer is the G-factor.

Explanation:

The G-factor, also referred to as general intelligence, is the mental skill which allows people to perform well in different areas. This factor is responsible for the overall results of intelligence tests, which means people who do well in one area (e.g. logical skills) tend to do well in others.

answer; i believe the correct answer is prefrontal cortex;