It costs Tom's T$-$shirts $$10\mathrm{.}00$ to produce each of its newest T$-$shirts, and they sell each one for $$16\mathrm{.}50.$ The $$6\mathrm{.}50$ Tom's earns from each shirt is its

A$.$ discount

B$.$ breakeven

C$.$ variable cost

D$.$ fixed cost

$$ E$.$ markup