Answer
(c) A and B
Work Step by Step
In simple harmonic motion at any instant the sum of kinetic energy and potential energy is equal to total energy and is constant, that is
$K.E + P.E = T.E = constant$
where $T.E$ is Total Energy
Also in simple harmonic motion Kinetic energy and Potential energy are interchangeable. Decrease in Potential energy results in increased Kinetic energy so as to keep Total Energy constant. When $ P.E = 0$ then $ K.E= K.E_{max}= T.E$ and when $K.E = 0$ then $ P.E= P.E_{max} = T.E$.
Thus we have
$K.E_{max} =T.E =P.E_{max}$
$\implies K.E_{max} =P.E_{max}$
