Two same digits that add up to "4" in the last digit, hence it must be either 2 or 7.  If we try digit 2, 42+52=94, wrong.  If we try digit 7, 27+57=104. correct. 
Aline writes a correct calculation. Then she covers two digits which are the same with a sticker:  [insert pic]  What digit is under the stickers? 
A: $$2$$ 
B: $$4$$ 
C: $$5$$ 
D: $$7$$ 
E: $$8$$ 