Match the following.

List I (Element)	List II (Block)
A Ra	I p - block
B Uuq	II s- block
C Ds	III f - block
D Fm	IV d - block

The correct answer is

Identify the pair of element in which the number of $s$-electrons to $p$-electrons ratio is $2: 3$

Which of the following has the least electron gain enthalpy?

Assertion (A) First ionisation enthalpy of oxygen is less than that of nitrogen.

Reason (R) Atoms with half-filled or completely filled orbitals are less stable.

The correct option among the following is