选B
develop into...
(使)发展成,变成…
She has developed into a beautiful girl.
她出落成一个美丽的姑娘.
The city has developed into a center of industry.
这座城市已经发展成为一个工业中心.
This trifle developed itself into a serious problem.
这件小事已发展成一个很严重的问题.