Any efficient allocation has to be such that everyone would agree to switch to that allocation from the endowment allocation -- or at least no one would object to such a switch.

Answer the following statement true (T) or false (F)

False

Rationale: That is true for mutually beneficial allocations -- which are mutually beneficial with reference to the endowment allocation. But it is not true for efficient allocations -- it's generally efficient to give everything to one person, even if that makes everyone else worse off. That's because an allocation is efficient so long as it cannot be changed in a way as to make some people better off without making anyone else worse off -- and that is the case at an allocation where one person gets everything.