\textbf{186.} The mutual inductance of a solenoid is $0.05\,\text{H}$ and the electric current passing through it in SI is given by $I = 0.4\sin(500\pi t)$. What is the magnitude of the induced EMF in the solenoid at the moment $t = 0.1\,\text{s}$, in volts?
\begin{itemize}
\item[(1)] $1.57$
\item[(2)] $3.14$
\item[(3)] $15.7$
\item[(4)] $31.4$
\end{itemize}