Answer:
D) a pair of diastereomers
Explanation:
The reaction is commonly referred to as the oxomercuration of alkenes. It involves the reaction of an alkene with mercury (II) acetate, then sodium borohydride, NaBH4. The product is an alkanol.
The mechanism of this reaction is shown in the image attached. We can see that the product contains two chiral centers. The reaction yields a pair of diastereomers.