A ball thrown horizontally with velocity v from the top of a tower of height h reaches the ground in t seconds. If another ball of double the mass is thrown horizontally with velocity 3v from the top of another tower of height 4h. If the first ball reaches  the ground at a horizontal distance d, the second ball reaches the ground at a horizontal distance

• A

  6d

• B

  3d

• C

  12d

• D

  4d