Answer:
B. A general intelligence that underlies successful performance on a wide variety of tasks
Explanation:
Charles Spearman was a psychologist that proposed a theory of intelligence. According to his theory, there is a general intelligence that influences a person's performance when they do a variety of tasks. In other words, he proposed that there is a general intelligence. This general intelligence that underlies successful performance is known as g factor.
Therefore, Spearman's g factor refers to a general intelligence that underlies successful performance on a wide variety of tasks