Ass$$me that product Alpha is $$2$ per unit and product Beta is priced at $$1$ per unit and that Ellie has $$20$ to spend on Alpha and Beta. She buys $4$ units of Alpha and $12$ units of Beta. The marginal utilities of the last unit of Alpha and Beta that she purchases are $40$ utils and $20$ utils, respectively. This indicates that

Select one or more:

a$.$ in order to maximize utility, Ellie should buy more Alpha and less Beta.

b$.$ in order to maximize utility, Ellie should buy more Beta and less Alpha.

c$.$ Ellie should make no change in consumption.

d$.$ given another dollar, Ellie should buy an additional unit of Beta.