How many ways can you place 2 knights such that they do not attack each other

This came out for one of the math tests.
How many ways can you place a White Knight (W) and a Black Knight (B) on an 8x8 chess board such that they do not attack each other?

(A) 1680
(B) 1712
(C) 3696
(D) 3760
(E) None of the above
If you select E state your explanation, I wonder how you can solve this!

I am not helping you to do your tests 

(C) 3696

I calculated from outside to inside in squares and the strat is to eliminate every square which one knight attacks and the square of the knight itself. If a knight is on a1 you eleminate the square a1 itself, b3 and c2 which would mean there are 61 safe squares for the other knight.

1st row: corner: 4x61

              next to corners: 8x60

              rest of 1st row: 16x59

2nd row: "corner": 4x59

                  rest of 2nd row: 16x57

3rd and 4th row:  16x55

<=> 4x61+8x60+16x59+4x59+16x57+16x55 = 3696

bro actually did the math

it was quite interesting