A particle is dropped from point A at a certain height from ground. It falls freely and passes through three points B,C and D with BC=CD.Time taken for particle to move from B to C is 2 seconds and from C to D is 1 second. Time taken to move from A to B is

Question

$$(a)\;0.5 s\quad (b)\;1.5 s \quad (c)\;0.75s \quad (d)\;0.25s$$