Question

___ was on television made me angry
It
The story
What
When

Answer 1

"What" is the appropriate answer.

Answer 2

What was on television made me angry.

It and when are irrelevant. The answer would have been The story, if the sentence was like this:

The story that was on television made me angry. Because of absence of 'that' this cannot be the answer. So the best option is 'What'