Management over Commerce for sure.
The most important skill in running your own business is the ability to manage people and issues - that's why people who are in charge are called Managers or General Managers. It's ok if you, for example, didn't understand accounting.
There's a reason why business owners hire accountants, rather than do accounts themselves. What you need to be able to do is manage your accountants, especially if your business ever grows large enough to hire multiple full-time accountants or maybe even establish its own accountant department.
Similarly, who cares about economics if you're going to run a national car-washing business, for example? Are you really going to sit there analysing supply and demand (economics)? Or run some CAPM model (finance)? You only undertake these majors because you can't start your own business and need to get a graduate job where you're just one of the many cogs in an entire machine.
I'm not sure what business administration is so I can't comment on that.