The correct options are
A A = 9
C B = 8
D D = 58
Cumulative frequency is sum of all the previous frequencies.
So, A = 9
For C,
9 + 12 = C
C = 21
For B,
C + B = 29
21 + B = 29 ∴ C = 21
B = 29 - 21
B = 8
For D,
54 + 4 = D
D = 58
Thus, A = 9, B = 8, C = 21 and D = 58.