Which of the following profit functions exhibits a Cobb$-$Douglas production function?

Group of answer choices

$\backslash$pi $=$ P $\backslash$times min$(2$L$,5$K$)20$L $35$K

$\backslash$pi $=$ P $\backslash$times $(3$K $+4$L$)20$L $35$K

$\backslash$pi $=$ P $\backslash$times K$0\mathrm{.}75$L$0\mathrm{.}5020$L $35$K

$\backslash$pi $=$ P $\backslash$times $(3$K$0\mathrm{.}5+4$L$0\mathrm{.}5)1/0\mathrm{.}220$L $35$K