The correct order of electronegativity on the Pauling scale is:

Solution

1. Electronegativity increases as we move from left to right across the second period.
2. The elements are $\text{C}(Z=6),\text{N}(Z=7),\text{O}(Z=8),\text{F}(Z=9)$.
3. The effective nuclear charge increases in the order $\text{C}<\text{N}<\text{O}<\text{F}$.
4. Therefore, the electronegativity follows the same order.
5. Hence the answer is (A).