A steady current flows in a metallic conductor of non-uniform cross-section. The quantity/ quantities constant along the length of the conductor is/ are.
(A) Current electric field and drift speed
(B) Drift speed only
(C) Current and drift speed
(D) Current only

Hint
The other name of steady current is constant current. The kind of current that does not change the intensity along with the time is known as steady current. The current is DC or direct in nature. Based on this concept we have to solve this question.

Complete step-by step answer
When a steady current flow in a metallic conductor of non-uniform cross-section then the drift speed is ${V_d} = \dfrac{I}{{neA}}$and the electric field $E = \dfrac{I}{{pA}}$.
$\Rightarrow$${V_d} \propto \dfrac{1}{A}\;and\;E \propto \dfrac{1}{A}$
$\Rightarrow$ Only current remains constant.
In a metallic conductor of non-uniform cross-section. Only current remains constant along with the entire length of the conductor.
Hence, the correct answer is Option (D).

Note
The conductor is defined as an object or any type of material that will allow the flow of charge or the electrical current in one or even sometimes more than one direction. The electrical current is allowed to pass through them because of the presence of the free electrons in them. The free electrons are present inside every atom that makes up the material.