what is the complete factored form of 9x³-64y³?

a.(3x-4y)(9x²+12xy+16y²)
b.(3x+4y)(9x²+12xy+16y²)
c.(3x-4y)(9x²-12xy+16y²)
d.(3x+4y)(9x²-12xy+16y²)​​