Answer:
I am on a diet, yet I keep thinking about the chocolate cake in the kitchen
Step-by-step explanation:
This sentence is correct because it used a comma and a conjunction (yet) to connect the two parts of the sentence. In the first, the subject is I and the verb is am. On a diet is a preposition phrase. In the second part of the sentence, I is once again the subject, but the verb is now keep thinking. Once again, the remainder of the sentence is a prepositional phrase that tells us about what the I is thinking.