The 'SOS' signal does not mean 'Save Our Souls'.
Why it is true
It was chosen only for its simplicity in Morse code (three dots, three dashes, three dots), making its transmission unmistakable.
Source: Communication 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.