What should come in place of question mark (?) in the following question ?
$$27\frac{1}{2}+15\frac{3}{4}-12\frac{2}{5}+18\frac{4}{5}$$

A

49

B

$$49\frac{13}{20}$$

C

$$49\frac{33}{20}$$

D

$$48\frac{13}{20}$$