2001 Gauss 7 Problem 21

Naoki wrote nine tests, each out of 100. His average on these nine tests is 68\%. If his lowest mark is omitted, what is his highest possible resulting average?

\textbf{(A)}\ 76.5\%\quad \textbf{(B)}\ 70\%\quad \textbf{(C)}\ 60.4\%\quad \textbf{(D)}\ 77\%\quad \textbf{(E)}\ 76\%

If there are no answer choices shown, enter a numerical answer.

Full credit to this problem is given to the CEMC, you may view all Gauss contests here.