Assertion. Electronic configurations of `Cr^(3+)` (containing 21 electrons) is same as that of `Sc (Z = 21)`, i.e., isoelectronic species have the same electronic configuration
Reason. Orbitals of atoms as well as ions are filled in order of increasing energy following aufbau principle
A. If both assertion and reason are true, and reason is the true explanation of the arrertion
B. If both assertion and reason are true, but reason is not the true explanation of the assertional
C. If assertion is true, but reason is false
D. If both assertion and reason are false