Assertion. The 19th electron in potassium atom enters into 4 s-orbital and not the 3 d-orbital
Reason. `(n +l)` rule is followed for determining the orbital of the lowest energy state.
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
