A Flat Coil Is Wrapped with 200 Turns of Very $18 \mathrm {~cm}$

A flat coil is wrapped with 200 turns of very thin wire on a square frame with sides $18 \mathrm {~cm}$ long. A uniform magnetic field is applied perpendicular to the plane of the coil. If the field changes uniformly from $0.50 \mathrm {~T}$ to $0.00 \mathrm {~T}$ in $8.0 \mathrm {~s}$ , find the emf induced in the coil.

A) $2.1 \mathrm { mV }$
B) $4.1 \mathrm { mV }$
C) $0.41 \mathrm {~V}$
D) $0.21 \mathrm {~V}$