In the given figure, MNP, SQP, NQR and MSR are straight lines. $$\angle NPQ = 54^{\circ}$$ and = $$\angle QRS = 68^{\circ}$$. What is the degree measure of $$\angle$$ SMN?

A

$$29^{\circ}$$

B

$$38^{\circ}$$

C

$$54^{\circ}$$

D

$$68^{\circ}$$