Counting All Stereoisomers,how Many Monochlorinated Products of the Free-Radical Chlorination

Counting all stereoisomers,how many monochlorinated products of the free-radical chlorination of (R) -2-bromobutane are possible? (Note that the starting compound is one enantiomer only.)

A) 3
B) 4
C) 5
D) 6
E) 8