The manufacturing costs of Calico Industries for three months of the year are as follows:

$\backslash$table$[[,$Total Cost,Production $($units$)],[$April$,$$$115,500,278,000],[$May$,88,500,168,000],[$June$,99,700,233,500]]$

Using the high$-$low method, the variable cost per unit and the total fixed costs, respectively, are

$$ a$.$ $$4\mathrm{.}50$ per unit and $$4,600$

b$.$ $$0\mathrm{.}25$ per unit and $$46,000$

c$.$ $$2\mathrm{.}50$ per unit and $$4,600$

d$.$ $$0\mathrm{.}45$ per unit and $$23,000$