In a Sing Thing, the first 4 singers sand song 1, the next 4 sand Song 2, and so forth. Song number 73 sang Song?

Question

A. 18
B. 19
C. 20
C. 73

I got 15 but I don't know.

Answer 1

Song 1: 1,2,3,4
song 2: 5,6,7,8
song 3: 9,10,11,12
...
song 9: 33,34,35,36
...
song ?: 73,74,75,76

Answer 2

song 1: 1,2,3,4
song 2: 5,6,7,8
song 3: 9,10,11,12
song 4: 13,14,15,16
song 5: 17,18,19,20
song 6: 21,22,23,24
song 7: 25,26,27,28
song 8: 29,30,31,32
song 9: 33,34,35,36
song 10: 37,38,39,40
song 11: 41,42,42,44
song 12: 45,46,47,48
song 13: 49,50,51,52
song 14: 53,54,55,56
song 15: 57,58,59,60
song 16: 61,62,63,64
song 17: 65,66,67,68
song 18: 69,70,71,72
song 19: 73,74,75,76

Therefore, the answer would be song #19