From what I can understand, this question is asking for what would describe the phrase "how many". In that case, the answers would be C and D, as they're both describing how many of whatever there is.
"There are four cats in that box."
Good Luck!
The answer is B) because the subject of a sentence is a person place or thing or a idea you can find the subject of a sentence once you find the verb Hope This Helps:)