If XAY means X² + Y² is
XBY means X² -Y² is
XCY means (X + Y)² is
XDY means (X - Y)² is
then what is true of the following?

XAY means X² + Y²

XBY means X² -Y²
XCY means (X + Y)²
XDY means (X - Y)²
Lets check by options:

= (7+3)² - (6-6)²

= 10² - 0

= 100

So, 100 = -100 (Does not follow)

= {(3+2)² - (5²-5²)}²

= {5² - 0 }2

= 25²

= 625

So, 625 = 624 (Does not follow)​

= {(3² +2²)}2 - {(5+4)2}2

= {(9+4)² - {(9)²}²

= 13² - 81²

= 169 - 6561

= -6392

So, -6392 = 88 (Does not follow)​

= (216 - 256)²

= (-40)²

= 1600

So, 1600 = 1600 (Follow)

Thus, the correct answer is (d).