Assume tony's marginal rate of substitution (mrs) of x for y is 12 -that is, mux muy 12 -the price of x is $39, and the price of y is $3. tony is spending too much of his income on y. do you agree or disagree? ○ a. o b. o c. o d. disagree. the mu per dollar spent on x is less than the mu per dollar spent on y. he should substitute y for x to increase utility. disagree. the mu per dollar spent on x is greater than the mu per dollar spent on y. he should substitute yfor x to increase utility. agree. the mu per dollar spent on y is greater than the mu per dollar spent on x. he should substitute x for y to increase utility. agree. the mu per dollar spent on xis greater than the mu per dollar spent on y. he should substitute x for y to increase utility.