Access Company's total utility costs during the past year were $$1,200$ during its highest month and $$600$ during its lowest month. These costs correspond with $10,000$ units of production during the high month and $2,000$ units of production during the low month. What are the fixed and variable components of its utility costs using the high$-$low method?

a$.$ $$0\mathrm{.}075$ variable and $$450$ fixed

b$.$ $$\mathrm{.}0120$ variable and $$0$ fixed

c$.$ $$0\mathrm{.}300$ variable and $$0$ fixed

d$.$ $$0\mathrm{.}060$ variable and $$600$ fixed