A horizontal straight wire 20 m long extending from east to west falling with a speed of `5.0 m//s`, at right angles to the horizontal component of the earth’s magnetic field `0.30 × 10^(–4) Wb//m^(2)`. The instantaneous value of the e.m.f. induced in the wire will be
A. 3 mV
B. 4.5 mV
C. 1.5 mV
D. 6.0 mV