Diazoniom ion help please?

Yes, the answer is II.

In step 1, diazonium ion 4-Br-Ph-N₂⁺ is formed.

In step 2, diazo coupling occurs. Phenol group is 2,4 directing. As position-4 of 4-methylphenol is occupied by methyl group, the coupling of the phenol occurs at position-2. The mechanism of step 2 is shown below.