Step 1: Understanding the Concept:
This question asks to identify the part of speech of the word 'spent' in the given sentence.
Step 2: Detailed Explanation:
- A verb is a word that describes an action, state, or occurrence.
- In the sentence "He spent a lot of money...", the word 'spent' describes the action that the subject 'He' performed.
- 'He' is the pronoun (subject).
- 'spent' is the action. It is the past tense of the verb 'spend'.
- Therefore, 'spent' is a verb.
Step 3: Final Answer:
The word 'spent' functions as a verb in this sentence. The correct option is (C).