Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : Ionisation enthalpy increases along each series of the transition elements from left to right. However, small variations occur. Reason (R) : There is corresponding increase in nuclear charge which accompanies the filling of electrons in the inner dorbitals. In the light of the above statements, choose the most appropriate answer from the options given below.

• Correct answer
  A

  Both $(\mathbf{A})$ and $\mathbf{( R )}$ are correct and $(\mathbf{R})$ is the correct explanation of $(\mathbf{A})$
• B

  Both $(\mathbf{A})$ and $(\mathbf{R})$ are correct but $(\mathbf{R})$ is not the correct explanation of $(\mathbf{A})$
• C

  $(\mathbf{A})$ is correct but (R) is not correct
• D

  (A) is not correct but (R) is correct

Hence, the correct answer is option: 'A'.