In comparison to LiAlH4, sodium borohydride is a _______ reducing agent that is capable of reducing _______.
a. milder; amides and carboxylic acids
b. more powerful; aldehydes, carboxylic acids, esters and amides
c. more powerful; esters, ketones and amides
d. milder, aldehydes and ketones
e. a and d
Answer: d. milder, aldehydes and ketones