Explanation:
I hope this is useful; please consider marking me as the best answer.
The example of a complex sentence that answers your question is: Processed foods should be avoided because they may cause significant health issues. Therefore, option C is the right choice.
A complex sentence consists of an independent clause and one or more dependent clauses. Unlike dependent clauses, independent clauses can function as standalone sentences since they express complete ideas. This is illustrated in the examples below.
a) Processed foods should be avoided (independent clause)
b) *Because they may cause serious health problems (dependent clause)
