根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。有两项为多余选项。
From 18－25, according to I．Q. scores；but you are wiser and more experienced with increasing age. You are smartest in your 20's; around 30, your memory begins to go down, particularly your ability to perform mathematical computations. __ Your vocabulary at the age of 45, for example, is three times as great as when you graduated from college. At 60, your brain has almost four times as much information as it did at the age of 21.You have the best physical sense of yourself from 15 to 24; the best professional sense from 40 to 49. Before the age of 24, we believe that our happiest years are yet to come；over 30，we believe that they are behind us. A National Health survey agrees: after the age of 30, we become more realistic and do not view happiness as a goal in itself. If we keep our health, achieve professional and emotional goals, happiness, we feel, will follow.
____ Generally between 30 and 39，but the peak (顶峰) varies with different professions(职业). Mosart wrote a symphony (交响曲)  and four sonatas by the age of 8, and Mendelssohn composed his bestknown work A Midsummer Night's Dream at 17, but most of the great music was written by men between 33 and 39.
Though the peak in most fields comes early, most Nobel Prize winners did their top research in their late 20's and 30's—creative people continue to produce work with high quality(质量) throughout their lives  ___

A．When are you most creative (创造性的)?

B．When are you happiest?

C．When are you smartest?

D．Do you know what I．Q. refers to?

E. But your I．Q. for other tasks goes up.
F. Creative people usually produce a lot of works.
G. For the “wellconditioned mind”， there is no upper limit..（限制）