He warned her _______ if she didn't think of something in the next twenty-four hours, there would be trouble.

He warned her _______ if she didn't think of something in the next twenty-four hours, there would be trouble.

• A. That
• B. Which
• C. Who
• D. Where

Answer: (A)

When talking about what someone warns about, the verb often needs a content clause that states the message or consequence. Here, the thing he warned her about is the statement that follows: if she didn’t think of something in the next twenty-four hours, there would be trouble. The word that introduces this content clause and ties it directly to the verb warn. It functions as the direct object of the verb, detailing exactly what was warned. The other options don’t fit because they would start a different kind of clause. Which would introduce a relative clause about a thing, who would refer to a person, and where would refer to a place—none of these convey the content of the warning itself.

When talking about what someone warns about, the verb often needs a content clause that states the message or consequence. Here, the thing he warned her about is the statement that follows: if she didn’t think of something in the next twenty-four hours, there would be trouble. The word that introduces this content clause and ties it directly to the verb warn. It functions as the direct object of the verb, detailing exactly what was warned.

The other options don’t fit because they would start a different kind of clause. Which would introduce a relative clause about a thing, who would refer to a person, and where would refer to a place—none of these convey the content of the warning itself.