b is the answer i hope this helped...
A. B. D. C. D, A, A, C, B, B, D, D
C I Believe , Have Ah Good Day
Answer
The frequency and the period are 45 cycles/second and 0.023 seconds
Explanation:
The frequency of the engine is given by :

We have, the engine increases its performance from zero to 2700 rpms.
Frequency,

The time period of the engine is given by :
T = f/f
So,

Hence, the required frequency and the period are 45 cycles/second and 0.023 seconds respectively.