The correct answer is A.
In the reaction shown below, the intermediate P is a tetrahedral intermediate. The product Q is a secondary alcohol.
The tetrahedral intermediate is formed when the nucleophile attacks the electrophilic carbon atom. The product Q is formed when the leaving group leaves the tetrahedral intermediate.
The other options are incorrect because they do not represent the correct intermediate or product.
Option B is incorrect because it does not represent the correct intermediate. The intermediate in option B is a trigonal bipyramidal intermediate.
Option C is incorrect because it does not represent the correct product. The product in option C is a primary alcohol.
Option D is incorrect because it does not represent the correct intermediate or product.