The enantiopure ketone shown (stereocentre fixed) is reduced with sodium borohydride, followed by work-up. Select the correct statement(s).

(R)-3-Phenylbutan-2-one has one stereocentre; reduction generates a second one at C-2. The product is a mixture of two diastereomers that are not formed in equal amounts, and each is optically active because the original stereocentre is retained. Diastereomers have different physical properties and can in principle be separated by chromatography or fractional distillation. The mixture is therefore not optically inactive.