What is the topic sentence here?

C. "Pennies also cost consumers and businesses money."

Explanation:

The topic sentence of a paragraph is the sentence that tells the reader what the main idea of the paragraph will be. It is usually the first sentence in a paragraph. It is broad and encompasses all of the information of the paragraph, while still being specific to exactly what information follows it. This sentence is the topic sentence because the rest of the paragraph is about how pennies cost people and businesses money.