2011广州一模英语一道题The ups and downs of life may seem unpredictabl

2011广州一模英语一道题
The ups and downs of life may seem unpredictable. But scientists know there are clear 1 that almost all people share. Even if you’ve passed your ―best‖, you still have other 2 years to come. Certain important high-points come later in life. When are you 3 ? From 18 to 25, according to I.Q. scores; but you’re （wiser） and more experienced with increasing age.
我们练习册上A.wiser B.clever,为什么选A而不是B?不是一样的意思吗?