The correct option is C Coordination number of C+ in the compound CD is 6
Radius ratio range: coordination number
0.155 - 0.225: 3
0.225 - 0.414: 4
0.414 - 0.732: 6
0.732 - 1.000: 8
Radius ratio of AB = A2+B2−=100300 = 0.33
Hence, coordination number = 4
Radius ratio of CD = C+D−=240480 = 0.5
Hence, coordination number = 6