so anytime is convenient, great.

There are two possible answer, none of which is a better options than the other, different company are looking for different answer:

1 - you want to climb the corporate ladder and want more responsibility => they want that answer if they are planning to grow the team and need people that will take the manager position when that happens

2 - you want stability and to become an expert at that one job, no plan to move (choose whichever personal project of yours outside of work is your focus here, family, house, dogs, sports....) => they want that answer if the team is already quite big and they already have "manager" potential in it. They now need people that will not quit for a better paying job quickly.

Not always, half the time they want to see if you are going to stay where you are and not try to look for another better paying job.

There is no right answer to this question because different employers are looking for different answers. Best is to answer honestly and if it's not what they wanted to hear it's actually best for you cause you dodge that bullet.

In 5 years, you'll be sitting with HR and argue about how professional is to fuck your boss's mom.