The correct answer is option 'C' - independent clause.

An independent clause, also known as a main clause, is a group of words that can stand alone as a complete sentence. It expresses a complete thought and contains both a subject and a predicate.

Let's analyze the given phrase "He ran out of options" to understand why it is an independent clause.

1. Subject:
- The subject of the sentence is "He." It refers to a specific person, but we do not know who exactly "he" is based on the given phrase alone. The subject is the doer of the action.

2. Predicate:
- The predicate of the sentence is "ran out of options." It contains a verb (ran) and an object (options). The verb "ran" indicates the action performed by the subject, and the object "options" is what the subject ran out of.

3. Complete thought:
- The phrase "He ran out of options" expresses a complete thought or idea. It provides sufficient information to convey a clear meaning to the reader or listener.

4. Can stand alone:
- An independent clause can function as a complete sentence on its own. In this case, "He ran out of options" can be considered a complete sentence because it contains a subject, a verb, and a complete thought.

Therefore, based on these observations, we can conclude that the given phrase "He ran out of options" is an independent clause. It satisfies all the criteria required for an independent clause to be classified as a complete sentence.