3. When you are describing a human subject (the person doing or being something in the sentence), an adjective clause begins with

When you are describing a human subject (the person doing or being something in the sentence),  an adjective clause begins with who or that.

Explanation:

An adjective clause is a group of words containing a subject and a verb. It offers further description or information - similar to what an adjective does - about something that was mentioned in another sentence. Adjective clauses are often introduced by relative pronouns such as who, which, when, where, whose or that.

If the clause is describing a human subject (the person doing or being something in the sentence), it must begin with either "who" or "that". If the clause is describing a non-human subject, it must begin with either "which" or "that". Since what is important in this question is the human subject, let's take a look at the examples below:

1. Look over there! That is the man who sold me a counterfeit watch! --> "who" refers to "man". "Man" performed the action of selling.

2. My sister is the girl that always wears a read sweater. --> "that" refers to "sister". "Sister" performs the action of wearing.

the correct answer is the name of the author of the quotation appears at the text leading up to it   apex 2018