Assertion: Manganin and constantan are widely used in standard resistors.
Reason: For manganin and constantan resistance, values would change very little with temperature.
Options:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false and R is also false.