Hi there, I've received a problem set back from my professor & I got these 3 questions wrong. He hasn't given me feedback so could I have some help on how to answer them.

1) If the marginal rate of substitution of the preferences of a consumer over bundles of two goods is negative for any bundle, which one of the following assumptions is definitely satisfied? a) Strict monotonicity. b) Weak monotonicity. c) Strict convexity. d) Weak convexity. 2) Which of the following results is true for the preferences over bundles of goods x and y represented by the utility function u(x, y) = 2x + 3 In(y) at an interior solution? a) Consumption of x is independent of income. b) Consumption of x is independent of px- c) Consumption of y is independent of income. d) Consumption of y is independent of Py. 3) Which of the following is definitely true for an inferior good that is not Giffen? a) Substitution effect is negative and income effect is positive after a decrease in its price. b) Its Engel Curve is positively sloped. c) Its substitution effect is always larger than its income effect in absolute value after a change in its price. d) An increase in its price increases its demand