What is the conclusion that can be derived from the given conditional proof?

a. (C ∨ G) ∨ R ⊃ (M ∨ D)
b. (S ∨ L) ⊃ (M ∨ D)
c. (G ⊃ M) ∨ (G ⊃ D)
d. (G ⊃ (M ∨ D)