Marbles of diameter $1.4 \;cm$ are dropped into a cylindrical beaker of diameter $7\;cm$ , Containing some water. The number of marbles that should be dropped into the beaker so that the water level increases by $5.6\;cm$ is _______

Question

$(A) \; 100 \\(B)\; 125 \\(C)\;130 \\(D)\;150 $