Which property does the statement illustrate?

Column A Column B

1.

If x – 3 = y and y = 8, then x – 3 = 8.

2.

If x + 2 = 7, then 7 = x + 2.

3.

If m = 2x and 2x = 7, then m = 7.

4.

If 2n – 4 = 5 + n, then 5 + n = 2n – 4.

A.

symmetric property

B.

transitive property please help me