A little late to answer, apologies for that... your exams have probably already come and gone...
In my opinion, for literature, you of course want someone with a good knowledge of language, writing, and media. I reckon your best shot would either be Osmium, because he's a writer, or Iridium, if you can find her. She's the one who taught Os' to write.
French, of course that's going to be Francium, no contest there. However, she only speaks French, which might be an issue... if you need someone who can speak both English and French, you probably want either Hoshi (Euro-151) or 152. They're both super multi-lingual. Either that or Nobelium, but he's quite grumpy so he might not be the best choice.
Economy, you could go with Nickel, but I'd recommend Hafnium. They work as a banker in their spare time, so I'm sure they'd know all the ins and outs of it.
Physics... you could probably choose any of the synthetics for that. Although, depending on the branch of physics, the choice would probably vary.
Maths, again you'd probably want someone good with numbers, such as Hafnium, or maybe Silicon? Although, probably the best catto with numbers would be either Iron, because he's always busy running the hotel, or maybe Cobalt? I heard he plays a lot of DnD, and that involves a lot of numbers.
Digital Society, I'm not quite sure what that would entail, but any catto versed in tech would probably be good, so you have quite a choice - Lithium, Silicon, Tantalum, or, hey... maybe even me! Who knows. I certainly don't.
Anyways, I hope your exams went well, friend.
