@HelpMeUnpickThis
My first thought, as someone who read Modern Languages at University, was to suggest Option C, but now that I have read your later post, which says that the subjects she enjoys most are STEM subjects, I would say, in all honesty, Option A.
I think that she may well feel an affinity with German (my own preferred language).
I think that German might stand her in good stead later on as her career develops, too.
If she does take German, she might like to browse these downloadable magazines. They were published for teenagers learning the language. They've stopped publishing them now, but the old ones are still fun to read.
https://de.maryglasgowplus.com/magazines/Das-Rad-78125
There are some French ones too.
https://fr.maryglasgowplus.com/magazines
For language books, by the way, there's a great choice at Foyles; the specialist retailer Grant and Cutler became part of Foyles some time ago.
Their language teams are really helpful.
https://www.foyles.co.uk/highlights/foreign-languages