When Adding Dressing to Salads

When adding dressing to salads,

A) the best time to add dressing is about one-half hour before serving to allow the greens to wilt a bit and absorb the flavor.
B) it is best to have the dressing at room temperature to improve its ability to coat the ingredients.
C) it is best to top the salad with the dressing without mixing.
D) it is best to only add enough dressing to lightly coat the salad ingredients.