Resolve x⁴/x3 + 1 into partial fractions.
A. x + 2/(x+1) − (x+1)/3(x²−x+1)
B. x − 1/3(x+1) + (x+1)/3(x²−x+1)
C. x + 1/3(x+1) − (x+1) 3/(x²−x+1)
D. x + 1(x+1) − (x+1)/3(x²−x+1)