Answer:
The answer is: a subject, a verb, and a complete thought
Explanation:
Independent clause is a type of clause that can stand alone and still have a meaning.
I like chocolate that is made in Switzerland. - this sentence consists of two clauses. The underlined clause is the independent one, we see that it can function as a sentence even without the dependent clause.
Its essential parts are subject, verb (predicate) and a complete thought. It also can contain objects, adverbials... but they are not a must.
