Consider an exchange economy with two agents, 1 and 2, and two goods, X and Y. Each agent's consumption set is in +R2. The endowments of agents 1 and 2 are (10, 1) and (0, 9) respectively. In any commodity bundle, the first entry is the quantity of X, and the second entry is the quantity of Y. If a>c, or a=c and b>d, then Agent 1 strictly prefers bundle (a,b) to (c,d). If b>d, or b=d and a>c, then Agent 2 strictly prefers bundle (a,b) to (c,d). Which of the following allocations is an efficient allocation?