I would go for one, you are confident to get a high grade in. I can't see any advantage in taking Physics, unless you prefer it. Psychology wouldn't be such a good choice, as it relates less, but depending on where you want to end up, it might be not as bad. (Business studies is somehow related in some areas, as e.g. human resources.) Philosophy might be a bit risky, because it might be difficult to predict, how good you will be, but otherwise it is a very academic and respected subject. Further Math depends on your abilities and of course wether the teaching suits you, but don't look to much at what others might not achieve.
Anyway, what subjects are you able to take?