Scientists in the world are expected to find a(n) _____ to the p

Scientists in the world are expected to find a(n) _____ to the problem of over population.
A、reply
B、solution
C、response
D、answer
【正确答案】：B
【题目解析】：reply回复；solution解决方案；response回应；answer答案句意：人们期望世界上的科学家能找到解决人口过剩问题的办法。