Sugar

-D-galactopyranose is a monosaccharide in the pyranose form, with the hydroxyl group on the C1 atom in the equatorial position. This is the characteristic feature of -D-galactopyranose, and it corresponds to the fourth structure provided in the options.

D-glucose is dextrorotatory, while D-fructose is levorotatory. This can be verified by analyzing their optical rotation. D-glucose rotates plane-polarized light to the right (clockwise), while D-fructose rotates it to the left (counterclockwise). Hence, the correct statement is that D-glucose is dextrorotatory and D-fructose is levorotatory.