As Initially Proposed,Spearman's "G" Factor and Thurstone's Set of "Primary

As initially proposed,Spearman's "g" factor and Thurstone's set of "primary mental ability" factors were not compatible with one another.Which of the following accurately describes subsequent research findings on this issue?

A) Thurstone's factors are largely unnecessary,because they can be almost fully explained by the g factor.
B) No substantial g factor really exists,and Thurstone's factors are mutually unrelated aspects of mental ability.
C) Both the g factor and the several additional factors are needed,but g is larger and more important than any other factor.
D) Both the g factor and the several additional factors are needed,but g is smaller and less important than most of the other factors.
E) None of the above;research findings have not resolved this issue.