I am asked to consider the reduction of acetaldehyde from the re and si faces. I am also asked whether the added hydrogen (labeled H* in my picture) is pro-R or pro-S in both cases. In my attached picture I replaced the added hydrogen (H*) with D to determine the absolute configuration.
If I did this correctly, addition of hydrogen from the si face results in a pro-S product with respect to the added hydrogen (H*). And addition of hydrogen from the re face results in a pro-R product with respect to the added hydrogen. Am I correct?