英语三级水平的问题it is time that the government _____ measures to pr

英语三级水平的问题
it is time that the government _____ measures to protect the rare birds and animals
a.takes b.took c.has taken d.taking
为什么不选a?
请帮忙把句子翻译下,根据句子的意思和语法帮我解释解释.

translate：是该政府采取措施去保护稀有鸟类和动物了的时候了.
It is time that...起虚拟语气作用.应为事实上并没有发生.
例句：
It is time that we planted trees there.
是到我们在那儿种树的时候了.
It is time that we took the problem seriously.
现在该是我们认真面对这个问题的时候了.
It is time that you reflected upon your mistakes.
该是你反省思过的时候了.