Crane Company sells insulated plastic tumblers with a unit contribution margin of $$21$ and a contribution margin ratio of $70\%.$ During the past month, the company sold $4900$ units and total fixed costs were $$29500.$ What is the unit selling price?

$$30\mathrm{.}00$

$$70\mathrm{.}00$

$$42\mathrm{.}35$

$$35\mathrm{.}70$