The correct answer is Syntax
Syntax is the part of the grammar that studies the arrangement of the words in the sentence and that of the sentences in the speech, as well as the logical relationship of the sentences to each other. When sending a verbal message, the sender seeks to convey a complete and understandable meaning. For this, the words are related and combined with each other. Syntax is an essential tool for satisfactorily handling the multiple possibilities that exist for combining words and sentences.