Assertion: If a ferromagnetic substance is filled inside a solenoid, its coefficient of self-induction L increases.
Reason: By increasing the current in a coil, its coefficient of self-induction L can be increased.
(A) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(B) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(C) Assertion is true but Reason is false.
(D) Assertion is false but Reason is true.