Answer:
Part a)
T = 0.52 s
Part b)

Part c)

Explanation:
As we know that the particle move from its maximum displacement to its mean position in t = 0.13 s
so total time period of the particle is given as

now we have
Part a)
T = time to complete one oscillation
so here it will move to and fro for one complete oscillation
so T = 0.52 s
Part b)
As we know that frequency and time period related to each other as



Part c)
As we know that
wavelength = 1.9 m
frequency = 1.92 Hz
so wave speed is given as



I believe the answer is A) Less work in less time.
The answer to this question is D or the last one