Suppose Good X and Good Y are perfect substitutes to each other. The marginal rate of substitution of X for Y is equal to 0.5. The price of Good X is $1 and the price of Good Y is $3. The consumer has a wealth level of 900. In the consumer's utility maximization market basket, what is the quantity of Good X?
a. 150
b. 0
c 300
d. 450
d. 900