c
\(\text { Here, } N=1000, I=4\, \mathrm{A}, \phi_{0}=4 \times 10^{-3}\, \mathrm{Wb}\)

Total flux linked with the solenoid, \(\phi=N \phi_{0}\)

\(=1000 \times 4 \times 10^{-3}\, \mathrm{Wb}=4\, \mathrm{Wb}\)

since, \(\phi=L I\)

\(\therefore \) Self-inductance of solenoid,

\(L=\frac{\phi}{I}=\frac{4\, \mathrm{Wb}}{4\, \mathrm{A}}=1\, \mathrm{H}\)