Answer:
d. fluid and crystallized intelligence
Step-by-step explanation:
Intelligence can be defined as a measure of the ability of an individual to think, learn, proffer solutions to day-to-day life problems and effectively make informed decisions.
Raymond Cattell was a psychologist who in 1963 the theory of intelligence. In his work he stated that, intelligence (intellectual abilities) can be divided into two (2) categories and these includes;
I. Fluid intelligence: it simply involves possessing the ability to think and reason in an abstract manner while solving problems. Thus, it is not dependent on formal education, learning or experience.
II. Crystallized intelligence: it involves possessing the ability to think and reason using one's experience or knowledge derived through formal education and learning.
Hence, according to Cattell, intelligence is a combination of fluid and crystallized intelligence.