Which one is healthy food ,the greens or ice-cream?

Question

按实际情况回答问题：Which one is healthy food ,the greens or ice-cream?
回答是 The greens（ ） healthy food. 用is 还是are

Answer 1

The greens（ ） healthy food. 用is追问

但课本有句这样的话：What are greens? Greens are vegetables.

追答

但是人家问哪个ishealthy food

你回答xxx are healthy food
这个是不是与问句矛盾了呢

Answer 2

用is the greens是特指,指这一类所以用is.你课本上的是泛指所以用are

Answer 3

选择 are 因为意思是绿色蔬菜的意思。