The correct answer is A.
The reaction is an electrophilic aromatic substitution reaction. The electrophile is the benzyl carbocation, which is generated by the reaction of benzyl bromide with potassium tert-butoxide. The nucleophile is the water molecule. The major product is the benzyl alcohol, which is formed by the attack of the water molecule on the benzyl carbocation.
Option B is incorrect because it is the benzyl bromide. The benzyl bromide is the starting material in the reaction. It is not the major product.
Option C is incorrect because it is the benzyl ether. The benzyl ether is a minor product in the reaction. It is formed by the reaction of the benzyl carbocation with the ether oxygen.
Option D is incorrect because it is the benzyl acetate. The benzyl acetate is a minor product in the reaction. It is formed by the reaction of the benzyl carbocation with the acetate ion.