The A comes from the question,,,, The ? variable is the part of the experiment that is being tested or the part that is changed by the person doing the experiment. Therefore I put independent causing the A so I hope that is right.
well i 'explanatory' is 11, but I'd say independent is right, but that's not working with dependent (not that explanatory would) and I can't think of a different word than dependent.
EDIT: I had meant using explanatory instead of independent in my previous post