Which of the following statements about prescriptive and descriptive grammar is correct?

The question is not complete because it doesn't include options.

There are two approaches to language; descriptive and prescriptive grammar.

Prescriptive grammar explains or prescribes how the language should be used. For example "Don't split infinitives" is a prescriptive rule.

Descriptive grammar shows or describes how a language is used by people, not saying how it should be used.

According to prescriptive grammar, a sentence is grammatical only if the native speaker uses it in his or her speaking. However, descriptive grammar explains how a sentence is produced through mental processes.