The correct option is C 57
The given series 57, 54, 58, 55, 59, 56, 60, ? is a combination of two series.
1st series: 57, 58, 59, 60 2nd series: 54, 55, 56, ?
Here, each term is increases by one.
Clearly, 56 + 1 = 57
Hence, option (D) is the correct answer.