The at symbol was chosen for email because it meant at the price of.
Why it is true
Ray Tomlinson chose the symbol in nineteen seventy-one because it was used in accounting to indicate prices and was not used in computer system commands, avoiding conflicts.
Source: Email History
Would you rather be asked first?
This is the reading side of the site, so the answer is in the sentence above — that is the whole point of it. Test yourself works the other way round: the question comes on its own, and the fact and the explanation only appear once you have answered.
