यदि A = {3,6,9,12,15,18,21}, B = {4,8,12,16,20}, C = {2,4,6,8,10,12, 14,16}, D = {5,10,15,20}, , तो निम्नलिखित को ज्ञात कीजिए:
C - B

Answer

{2,6,10,14}