the answer is a because
set a has 11 dots:
20 has 1 dot
30 has 3 dots
40 has 2 dots
50 has 4 dots
60 has 1 dot
Total set A has 11 dots
1+3=4
4+2=6
6+2=10
10+1=11
Set B has 12 dots:
10 has 1 dots
20 has 3 dots
30 has 4 dots
40 has 2 dots
50 has 1 dot
60 has 1 dot
Total set B has 12 dots