The phase constant in rad of a simple pendulum whose amplitude of oscillation is 2; initial displacement is 1, initial velocity is 4 units/sec, frequency in rad/sec is 6 is:

Question

$\begin{array}{1 1}(a)\;1 \\(b)\;\frac{1}{2}-\frac{1}{3} \\( c)\; \frac{1}{2}+\frac{1}{3} \\(d)\;0 \end{array}$