Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The first ionisation enthalpy decreases across a period.
Reason R: The increasing nuclear charge outweighs the shielding across the period.
In the light of the above statements, choose the most appropriate from the options given below:

A

Both A and R are true and R is the correct explanation of A

B

A is true but R is false

C

A is false but R is true

D

Both A and R are true but R is NOT the correct explanation of A