my friend was in a similar position to you and she chose to take three science subjects (maths, chemistry and biology) because after assessment she thought it would be worth it. i agree with the comments here if you enjoy and feel you'll perform better taking english and history then option C is great. however if you feel you can work towards maths, will enjoy it and will be motivated to work for it then i would say ideally option A is a great choice. there's a lot you can do with it career wise as you mentioned, it's nice as the lesson structure will be different you'll have your essay more discussion subject, your sciences and maths being a more numerical, logical, problem solving subject. my friend chose option A if you're interested, the exact same combination of subjects. i wouldn't take maths if you don't feel like you'll want to work for it, if you've got the dedication to work for it i'm sure despite how tough it may be, it'll get better, that's for any of your subjects. it won't just be you, even people great at particular subjects will struggle. if you feel maths really will be a headache, then i'll say option C is your next best choice.