To follow is information about the units produced and total manufacturing costs for Pine Enterprises for the past six months.

Using the high $-$ low method, what is the variable cost per unit?

A$.$ $$1\mathrm{.}01$

B$.$ $$1\mathrm{.}66$

C$.$ $$0\mathrm{.}34$

D$.$ $$2\mathrm{.}96$