What's the population of the country?能不能回答为It's...请说明下原因!

What's the population of the country?能不能回答为It's...请说明下原因!
What's the population of the country?能不能回答为It's...
请说明下原因!

What's the population of the country?能不能回答为It's...请说明下原因!
应该可以
population作为集体名词,但是常用做单数,所以用is做谓语是可以的