If orbital velocity of planet is given by \[v={{G}^{a}}{{M}^{b}}{{R}^{c}}\], then [EAMCET 1994]

• A.             \[a=1/3,\,b=1/3,\,c=-1/3\]
• B.             \[a=1/2,\,b=1/2,\,c=-1/2\]
• C.               \[a=1/2,\,b=-1/2,\,c=1/2\]
• D.             \[a=1/2,\,b=-1/2,\,c=-1/2\]