An option is one of many possibilities which you can choose from.
A choice is your preference from two or more options.
If something is a variant then it is the same but with a small difference.
- I had three options: to walk, to cycle or to get the bus.
(many possibilities) - My choice was to cycle.
(my preference) - The Rolls Royce Trent 970-84 engine is a variant of the Rolls Royce Trent 900.
(both engines are the same but small differences)
