Which of the following pair of terms are like terms?

Terms having same algebraic factors are called like terms.

Terms having different algebraic factors are called unlike terms.

Let us consider the terms xyz and 7zxy.

Here, xyz has factors 1, x, y, and z.

7zxy has factors 7, x, y, and z.

Since xyz and 7zxy have the same algebraic factors x, y, and z, they are like terms.

Thus, the terms given in alternative C are like terms.