Which of the following shows how the number 7 can be rewritten with the difference of squares identity?

1. (16 - 9) = (4 + 3) (4 - 3)

2. (18 - 11) = (9 + 6) (9 - 5)

3. (25 - 4) = (5 + 2) (5 - 2)

4. (16 - 9) = - 1 (4 + 3) (4 - 3)

5. (64 - 1) = (8 + 1) (8 - 1)

If we let x and y be the two numbers such that the difference of their squares will give 7, we have the equation,

x^2 - y^2 = (x + y) (x - y) = 7

From the given choices, the squares are 16 and 9 which are squares of 4 and 3, respectively. Therefore,

16 - 9 = (4 + 3) (4 - 3) = 7

Thus, the answer is letter A.