Assertion : In transition elements radii of 5d series are virtually the same as those of the corresponding members of 4d series.
Reason : The filling of 4f orbitals before 5d orbitals results in regular decrease in atomic radii.
A. If both assertion and reason are true and reason is the correct explanation of assertion.
B. If both assertion and reason are true and reason not is the correct explanation of assertion.
C. If assertion is trun but reason is false.
D. If both assertion and reason are false.
