My sister got this question for one of her tests. 

> 
> There are many obstacles **\_\_** the road to success.
> 
> 
> 

Her options were: 

> 
> 1. across
> 2. along
> 
> 
> 

I initially thought that *across* would make more sense here, as it conveys the meaning “from one side of the road to the other” as in a block of wood placed across my path. However, *across* could also mean “on the other side” as in “I live across the road”. Therefore, *across* seems like the more ambiguous term here when compared to *along*.

*Along*, therefore, seems like the better choice here. However, it can be argued that *along* doesn’t necessarily give the impression that the obstacles “cross” my path.

What would be the appropriate term here?