Which of the following is a true statement about the function of a topic sentence?

It is the most important sentences in a paragraph
It’s sums up a minor detail of the paragraph
The only appears in the introductory of the paragraph
Represents the main idea of the entire composition

The statement that represents the main idea of the entire composition is true about the function of a topic sentence.

The correct statement about the function of a topic sentence is:

It represents the main idea of the entire composition.

The correct statement about the function of a topic sentence is: "It represents the main idea of the entire composition."

To arrive at this answer, you can analyze the options and eliminate the incorrect ones.

Option 1 states that a topic sentence is the most important sentence in a paragraph. While it is true that a topic sentence is significant, it is not always the most important sentence in the paragraph. Therefore, this option is incorrect.

Option 2 suggests that a topic sentence summarizes a minor detail of the paragraph. This is not accurate since a topic sentence should encompass the main idea, not a minor detail. Therefore, this option is incorrect.

Option 3 claims that a topic sentence only appears in the introduction of the paragraph. However, a topic sentence can be found in different parts of a paragraph, such as the beginning or even in the middle. Consequently, this option is incorrect.

Option 4 correctly states that a topic sentence represents the main idea of the entire composition. The topic sentence serves as a guide by presenting the primary point that the writer wants to convey. It provides a clear focus for the paragraph and the composition as a whole. Thus, this option is the correct statement about the function of a topic sentence.