____ sign is used at the end of a sentence or a short phrase which express strong feelings.

An exclamation sign (!) is used at the end of a sentence or phrase to express strong emotions, such as surprise or excitement. In English punctuation, it conveys intensity or emphasis, distinguishing it from other marks. Options A (question mark, for inquiries), B (comma, for pauses), and D (period, for statements) serve different purposes and do not indicate strong feelings, making C the correct choice for this punctuation rule.