Elisa reads $2$ pages of her book on Day $1$.  Then Mr Scan reads $4$ pages of her book on Day $2$, $8$ pages on Day $3$, and then $16$ pages on Day $4$, which continues until Elisa finishes her book.  If there are $254$ pages in her book, how many days does it take her to read the whole book? 
选项为:A:$$5$$ days  B:$$6$$ days  C:$$7$$ days  D:$$8$$ days  E:$$9$$ days  请回答其中一个选项.