Choose the correct answer from the given alternatives
Maxwell in his famous questions of electromagnet introduce the concept of:
A. Ac current
B. Displacement current
C. Impedance
D. Reactance

Hint: Maxwell's electromagnetic theory of light, a theory in physics that consists of electromagnetic wave motion principles.

Complete step by step answer:
As we know by these four equations of Maxwell complete electromagnetism can be explained. Complete electromagnetism is based on these four fundamental equations of Maxwell. It is not only discovered by Maxwell, it is discovered by Gauss, Faraday and Ampere but Maxwell explains these equations so these are known as Maxwell’s electromagnetism equation.
We also know that every charge produces the electric field.
Maxwell’s four equations describe the electric and magnetic fields arising from distributions of electric charges and currents, and how those fields change in time. They were the mathematical distillation of decades of experimental observations of the electric and magnetic effects of charges and currents.
Maxwell’s Equation are:
1. \[\nabla .E=\dfrac{q}{{{E}_{0}}}\]
2. \[\nabla .B=0\]
3. \[\nabla \times E=\dfrac{dB}{dt}\]
4. \[\nabla \times E={{\mu }_{0}}J+\dfrac{1}{{{c}^{2}}}\dfrac{dE}{dt}\]
So, by considering the last equation written,
\[\nabla \times E={{\mu }_{0}}J\] is the Ampere’s equation.
So, Maxwell modified Ampere's equation and introduced the Concept of displacement current.
So, displacement current \[=\dfrac{1}{{{c}^{2}}}\dfrac{dE}{dt}\]

Hence, the correct answer is option B.

Note:
Maxwell's equations describe how electric charges and electric currents create electric and magnetic fields. They describe how an electric field can generate a magnetic field and vice versa.