$10.$ You write a poem using four sheets of paper with one pencil. Denote the number of sheets

of paper and the number of pencils used to write poems by x$1$ and x$2,$ respectively. What is the

production function, which allows you to write one poem when you are given one sheet of paper

and ten pencils?

A$.$ f $($x$1,$ x$2)=$ min $\{$x$1,4$x$2\}$

B$.$ f $($x$1,$ x$2)=$ min $\{$x$1/4,$ x$2\}$

C$.$ f $($x$1,$ x$2)=$ x$1/4+$ x$2$

D$.$ f $($x$1,$ x$2)=$ min $\{$x$1/10,$ x$2\}$

E$.$ f $($x$1,$ x$2)=$ min $\{10$x$1,$ x