$(a)$ Potential energy is always equal to its $K.E.$
$(b)$ Average potential and kinetic energy over any given time interval are always equal.
$(c)$ Sum of the kinetic and potential energy at any point of time is constant.
$(d)$ Average $K.E.$ in one time period is equal to average potential energy in one time period.
Choose the most appropriate option from the options given below:
(for $1$ time period)

$2\,\frac{{{d^2}x}}{{d{t^2}}} + 32x = 0$
where $x$ is the displacement from the mean position of rest. The period of its oscillation (in seconds) is