If a mass m is attached to a given spring, its period of oscillation is T. If two such springs are connected end to end and the same mass m is attached,

(a) Is the resulting period of oscillation greater than, less than, or equal to T?

(b) Choose the best explanation from among the following:

I. Connecting two springs together makes the spring stiffer, which means that less time is required for an oscillation.

II. The period of oscillation does not depend on the length of a spring, only on its force constant and the mass attached to it.

III. The longer spring stretches more easily, and hence takes longer to complete an oscillation.