If the equation for displacement of two particles executing S.H.M. is given by $\mathrm{y}_{1}=2 \sin (10 \mathrm{t}+\theta)$ and $\mathrm{y}_{2}=3 \cos 10 \mathrm{t}$
respectively, then the phase difference between the velocity of two particles will be $\ldots \ldots \ldots$
(A) $-\theta$
(B) $\theta$
(C) $\theta-(\pi / 2)$
(D) $\theta+(\pi / 2)$.