Step 1: Recall common adjective–preposition collocations in English. The adjective “pleased” is most frequently and naturally followed by the preposition with when expressing satisfaction or approval.
Step 2: Examine each option:
- “pleased about” — sometimes used, but it is less idiomatic and not the standard choice in most contexts.
- “pleased at” — occurs rarely and is generally restricted to very specific or formal uses.
- “pleased with” — is the standard and most widely accepted collocation in everyday and formal English.
Step 3: Since “pleased with” is the correct and natural collocation, the correct answer is (C).