$(50$ points$)$ Firm A wants to borrow $$10,000,000$ at a floating interest rate for $5$ years; Firm B wants to borrow $$10,000,000$ at a fixed interest rate for $5$ years. Their external borrowing opportunities are shown below:

$\backslash$table$[[,\backslash$table$[[$Fixed$-$Rate$],[$Borrowing Cost$]],\backslash$table$[[$Floating$-$Rate$],[$Borrowing Cost$]]],[$Firm A$,5\mathrm{.}00\%,$LIBOR$],[$Firm B$,5\mathrm{.}80\%,$LIBOR $+0\mathrm{.}30\%$