Correct option is C
(12, 7, 1385)
(19, 15, 3484)
Following logic is followed in the given question-
(1st )3 – (2nd)3 = 3rd Number
12, 7, 1385 → 123 – 73 = 1728 - 343 =1385
And
19, 15, 3484 → 193 – 153 = 6859 – 3375 = 3484
Similarly,
21, 16, 5165 → 213 – 163 = 9261 – 4096= 5165
Therefore, correct option is (c).