I'm biased, but I'm going with A
Cool isn't it? I write the old school lower case type of A like this - a. Anyone else do that? Or the boring kind - a?
S is my favourite . My reason being that it turns singular things into numerous things..... An example being...
Pound - pounds
Also
Beer - beers
Everton win - Everton wins
Everton,s transfer million - Evertons transfer millions