Corn and milo are perfect substitutes in a feed ration for chickens. The same energy is provided by either $1lb$ of corn or $1\mathrm{.}5lb$ of milo. If the price of corn is $$0\mathrm{.}10$ per lb while the price of milo is $$0\mathrm{.}08$ per $lb,$ the cost$-$minimizing producer would:

a$.$ Use $60\%$ corn and $40\%$ milo

b$.$ Use all corn

c$.$ Use all milo

d$.$ Use half corn, half milo