Assertion `:` Calgon is used in manufacture of soft water being used for laundry purpose.
Reason `: Ca^(2+)` and `Mg^(2+)` ions present in hard water are rendered ineffective by calgon forming their soluble complexes.
A. If both assertion and reason are true and the reason is the correct explanation of the assertion.
B. If both assertion and reason are true but reason is not the correct explanation of the assertion.
C. If assertion is true but reason is false.
D. If assertion if false but reason is true.