Suppose the marginal rate of substitution of x for y is given by

MRSx, y = 5x/7y

a) The indifference curves will be bowed away from the origin.

b) The indifference curves will be bowed in towards the origin.

c) The indifference curves will be straight lines.

d) It is not possible to tell the shape of the indifference curves with only

this information.

The answer is A. I don't know why. Please explain!