JEE Main Physics question

Two identical metal spheres are released from the top of a tower after seconds of each other, such that they fall along the same vertical line. If air resistance is neglected, then at any instant of time during their fall [Orissa JEE 2010]

• (A)The difference in their displacements remains the same
• (B)The difference between their speeds remains the sameCorrect
• (C)The difference between their heights above ground is proportional to
• (D)The difference between their displacements is proportional to