Because he couldn’t afford the alligator he wanted
The answer is option D: adverb.
<em>Sometimes </em>is an adverb of frequency, which indicates how often something happens. Adverbs of frequency are usually used for repeated or periodic activities, so they often go with the present simple tense. Other examples of adverbs of frequency are: <em>always</em>, <em>usually</em>, <em>often </em>and <em>never</em>.
Explanation:
1. The girl has to make the model of a volcano.