Which pair of atoms has the highest electron negativity difference?

You forget to include the pair of atoms. But I found similar questions that asks about the following pairs:

H - S

H - Cl

N - H

O - H

C - H

To be able to answer, we must find out the electronegativity of each atom

Electronegativity of H = 2.2

Electronegativity of S = 2.58

Electronegativity of N = 3.04

Electronegativity of Cl = 3.16

Electronegativity of O = 3.5

Electronegativity of C = 2.55

Since all these atoms are paired with H, and they all have electronegativity greater than H, the atom with the highest electronegativity (O) would pair with H to have the greatest electronegativity difference.

The answer is therefore, O - H