A Solution Containing 0 $\circ$ What Is the Specific Rotation of the R Isomer

A solution containing 0.04 g/mL of a pure S enantiomer in a 1 dm polarimeter rotates plane polarized light by +2 ^$\circ$ . What is the specific rotation of the R isomer?

A) "-50 ^$\circ$ "
B) "-20 ^$\circ$ "
C) "+10 ^$\circ$ "
D) "+50 ^$\circ$ "