This is actually a trick question. If you consider electricity as a stream, it must run downhill as a stream does, so both A and B may be true. Receptacles on either side of the GFCI receptacle can be protected by the receptacle. Physical positioning has nothing to do with how it is wired, so C may be true. A receptacle uphill of the GFCI receptacle can also be protected, assuming "uphill" is a physical position of the receptacle, so D may be true. Typical BS question with not enough information to make the correct choice. Obviously, the answer is E, all of the above.