Which one of the following statements is true with respect to optical activity?

Select an option to attempt

1. A
   A relationship exists between the (R) and (S) configurations of enantiomers and the direction [(+) or (−)] in which they rotate plane-polarized light.
2. B
   Equimolar mixture of D and L isomers of the same compound will be optically active.
3. C
   Meso compounds that are optically inactive may contain stereogenic centers or chiral centers.
4. D
   Optical activity is independent of temperature.