A magnetic flux passing perpendicular to plane of a coil is varying according to the relation. $\phi =3t^2+2t+5$ milliwebers. the emf induced at $t=2 \;sec$ is :

Question

$(a)\;14\;mV \\ (b)\;14\;V \\(c)\;-14\;mV \\(d)\;31\;mV $