Which of the following expressions are equivalent to 2/(x⁴-y⁴) ?
A. 2/(x²-y²) · 1/(x²+y²)
B. 2/(x²-y²) · 1/(x²-y²)
C. 1/(x²-y²) · 1/(x²+y²)
D. 2/((x²)²-(y²)²)