Given below are two statements : Statement (I) : When currents vary with time, Newton's third law is valid only if momentum carried by the electromagnetic field is taken into account. Statement (II) : Ampere's circuital law does not depend on Biot-Savart's law. In the light of the above statements, choose the correct answer from the options given below :

Statement I: "When currents vary with time, Newton's third law is valid only if momentum carried by the electromagnetic field is taken into account."

This is true. For time-varying currents, the electromagnetic field itself carries momentum. The mechanical momentum of the charges alone is not conserved; one must include the electromagnetic field momentum (given by $$\frac{1}{c^2}\vec{E} \times \vec{B}$$ per unit volume) for Newton's third law (conservation of momentum) to hold. This is a fundamental result in classical electrodynamics.

Statement II: "Ampere's circuital law does not depend on Biot-Savart's law."

This is false. For steady (magnetostatic) currents, Ampere's circuital law can be derived from the Biot-Savart law. The Biot-Savart law gives the magnetic field due to a current element, and integrating it appropriately yields Ampere's law. They are mathematically equivalent descriptions of magnetostatics, so Ampere's law does depend on (and is derivable from) the Biot-Savart law.

The answer is Option B: Statement I is true but Statement II is false.