There's a door at either end of the building?
A
The building has two ends and two doors
B
The building has two ends, but only one door
C
The building has two ends, but I do not know which of the two has a door
D
The building has many ending each and for all
Verified Correct Answer: A.
Grammar & Contextual Explanation
Either as used before the first of two given alternatives. When it is used as a determiner, it refers to both choices or possibilities
This means that there are two alternatives. At each end of the building, there is a door.
Either is used only when there are two persons or things. The statement can be interpreted as
''There are two ends in the building, and each of the ends has a door.
Source: Myschool Past Questions Archive (Record #12287)