A body of mass \[m\] hangs at one end of a string of length l, the other end of which is fixed. It is given a horizontal velocity so that the string would just reach where it makes an angle of \[{{60}^{o}}\] with the vertical. The tension in the string at mean position is [ISM Dhanbad 1994]

• A.             \[2\,mg\]
• B.                      \[mg\]
• C.             \[3mg\]
• D.             \[\sqrt{3}mg\]