Li's Marginal Rate of Substitution of Hamburger for Steak Is

Multiple Choice

Li's marginal rate of substitution of hamburger for steak is 1/4, and Zhang's marginal rate of substitution of hamburger for steak is 2. The allocation of hamburger and steak ____ Pareto-efficient between Li and Zhang because ____.

A) is; no trade can make both Li and Zhang better off
B) is; Zhang's MRS is exactly 8 times larger than Li's MRS
C) is not; if Li traded some amount of hamburgers to Zhang for some steak, it is possible that each can be better off
D) is not; if Li traded some amount of steak to Zhang for some hamburgers, it is possible that each can be better off