A size$-$exclusion column has a height of $20cm$ and a diameter of $1cm$ and the beads take up $60\%$ of the volume. You want to isolate a protein with a Kav of $0\mathrm{.}4.$ You are collecting $1mL$ fractions. Which one should have your protein?

A$)5$

B$)13$

C$)11$

D$)7$

E$)9$

F$)15$