According to the discussion of visual imagery during problem solving,

a. visual images can be nontraditional, so they are sometimes more helpful than symbols and other methods of representing a problem.
b. surprisingly, people who are high in visual-imagery abilities are no more likely than other people to use imagery effectively during problem solving.
c. visual imagery is helpful only if problem solvers are initially instructed to visualize a familiar object.
d. a disadvantage to visual imagery is that it can only be used if you have a clear idea about the solution to the problem.

Ans: a