Which type of pronoun is used to show the connection between the antecedent and the subordinate clause of a sentence

,A relative pronoun :)
Explanation- The type of pronoun that is used to show the connection between the antecedent and the subordinate clause of a sentence is called a relative pronoun. Relative pronouns are used to link a clause or phrase to a noun or pronoun. Relative pronouns include who, whom, which, whoever, whomever, whichever and that.

It shows that the milk is like life to the boy