Solution :
Remember that during reduction with $$NaB{H_4},$$ a hydride ion is transferred by $$NaB{H_4}$$ to carbonyl carbon and a proton ( or deutron ) is transferred from the solvent ( in the second step ) to carbonyl oxygen.
Releted MCQ Question on Organic Chemistry >> Aldehyde and Ketone
Releted Question 1
The reagent with which both acetaldehyde and acetone react easily is