1) You come to a fork in the road.
You need to make a choice between going left or right. You face a decision between the left path and the right path. You have the option to advance in either direction.
2) You go right.
Right was your choice. Right was your decision. Right was the option you selected.
In the case of 2), each of the three words is used to denote an alternative. Right is a choice, a decision, an option, or an alternative. In the case of 1), each word is used to denote a set of competing alternatives. "Left or right?" is a choice to be made, a decision to be faced, an option of which way to go, or a set of competing alternatives.
All three of these words seem to be ambiguous between 1) and 2) (and of course, there's nothing special about the fork in the road example; this is a general problem that can make it difficult to use these words effectively in some contexts). What I would like to ask for are two separate lists of a few words that are uniquely appropriate for 1), and a few other words that are uniquely appropriate for 2). Thus far it seems alternative and selection might work uniquely for 2), but I've come up with nothing at all uniquely applicable to 1).