A particle is moving in a circular path of radius a , with a constant velocity v as shown in the figure . The center of circle is marked by 'C' .The angular momentum from the origin O can be written as :

Question

$(a)\;va(1+cos \normalsize 2 \theta)\qquad(b)\;va(1+cos \normalsize \theta)\qquad(c)\;va cos \normalsize 2\theta\qquad(d)\;va$