“2 consecutive years” does not mean 2015 one level, 2016 another level, ad if you took a class in 2013 it doesn’t count due to the interruption. It means Level 1+2 (rather than Level 1 in two different languages).
So, the choices are:
1° Take Level 2 of the foreign language where he did poorly (I wouldn’t recommend)
2° Summer community college, take Level 1 of a foreign language offered at his high school (French is easiest unless Italian is offered, Spanish is most common), then take Level 2 in the Fall.
And he’s done, probably could fit both Cs and physics this way.