The fundamental premise upon which F. C. Donders based his method for studying mental processes was that

a. there are individual differences in the procedures people use to solve mental problems.
b. extra mental steps will result in more time to perform a task.
c. the mental processes of children are qualitatively different from the mental processes of adults.
d. participants can be made aware of their own mental processes.

Answer: b. extra mental steps will result in more time to perform a task.