Classify the given differential equations as to whether they are (a) separable, (b) exact, or (c) linear. Solve the given differential equations using an appropriate method.
(x³ + y³)dx + 3xy² dy = 0
A) Separable; y³ = -x³ + C
B) Exact; x³ + y³ = C
C) Linear; y³ - x³ = C
D) Separable; y³ + x³ = C
