If none of your proposed solutions completely solve an identified problem, but several solve?

When in doubt, mumble; when in trouble, delegate; when in charge, ponder.

Humor aside, measure the solutions by their pros & cons in each aspect. It pretty rare you get a perfect one for everything. We like to say a solution can be (1) fast, (2) cheap, (3) good - pick two of the three. So first of all, this is the client's choice. Beyond that, need to go with your gut.
An inefficient solution would mean extending the wait, would the user be okay with that? Depends on the kind of user. Requiring high frequency of maintenance works both ways, could mean extra $ per visit, additional annoyance, disgruntlement on the user side. A missed deadline could just go whoosh out the window or tear the contract apart.
Moreover, sometimes you need to break out of the box you're in to do better. Fresh perspective helps, either meeting with others (mayhap project managers) or permitting the mind to wander away to other things. I've had one case where an unrelated solution popped out as integral to a year old problem, whilst it slumbered in the back of the mind.