Which Species Is Reduced in the Reaction 2 MoCl₅(s)+ 5 $\to$

Which species is reduced in the reaction 2 MoCl₅(s) + 5 Na₂S(s) $\to$ 2 MoS(s) + 10 NaCl(s) + S(s) ?

A) Cl in MoCl₅
B) Na in Na₂S
C) Mo in MoCl₅
D) S in Na₂S
E) S solid