Aset of keys on the end of a string is swung steadily in a horizontal circle. In one trial, it moves at speed v in a circle of radius r. In a second trial, it moves at a higher speed 4v in a circle of radius 4r. In the second trial, how does the period of its motion compare with its period in the first trial?

A.

It is the same as in the final trial.

B.

Itis 4 times larger.

C.

Itis 16 times larger.

D.

Itis one-fourth as large.