Notice the following properties of equality:
1. The Addition property of equality states that, if:

Then:

2. The Subtraction property of equality states that, if:

Then:

3. The Transitive property of equality states that, if:

Then:

4. The Symmetric property of equality states that, if:

Then:

For this case, you have the following equation:

If you subtract 2 from both sides of the equation, you are applying the Subtraction property of equality:

Therefore, the answer is: Last option (Subtraction property of equality)