Which of these reactants will not generate this racemic amine?
This is an example of reductive amination, which generally proceeds through two main steps: (i) condensation reaction between the amine and carbonyl to generate an imine; and (ii) reduction of the imine to the corresponding amine.



Clearly (e) can't do this reaction since there is no carbonyl. The reason why (a) is also an answer comes down to the wording of the question - it specifically states that the product is racemic. The stereocentre in (a) is (R) in the starting material, and is not involved in the reaction so the product will exist as a single (R) enantiomer.