Consider the following reaction and statements:
[Co(NH₃)₄Br₂]⁺ + Br^- $$\to$$ [Co(NH₃)₃Br₃] + NH₃
(I) Two isomers are produced if the reactant complex ion is a cis-isomer
(II) Two isomers are produced if the reactant complex ion is a trans-isomer
(III) Only one isomer is produced if the reactant complex ion is a trans-isomer
(IV) Only one isomer is produced if the reactant complex ion is a cis – isomer
The correct statements are

Phenol reacts with methyl chloroformate in the presence of NaOH to form product A. A reacts with Br₂ to form product B. A and B are respectively :

The major product of the following reaction is:

The predominant form of histamine present in human blood is (pK_a, Histidine = 6.0)