Venture capitalists are engaged with a start$-$up for $\_\_\_\_$ years $,$ while multi$-$year grants from foundations last $\_\_\_\_$ years on average.

A$.10$ to $14$ :$5$ to $7$

B$.2\mathrm{.}5$; $5$ to $7$

C$.5$ to $7$; $2\mathrm{.}5$

D$.5$ to $7$;$10$ to $14$