My father was so poor ________?

That he could not buy our food

That who could not buy us food

To he could not buy us food

That he could not buy us food

Explanation

The sentence should read: "My father was so poor that he could not buy us food."

This sentence is a common idiomatic expression used to describe someone's extreme poverty.

The phrase "so poor" is an intensifier, emphasizing the extent of the poverty, and the clause "that he could not buy us food" explains the severity of the situation.