PT DEF's sales reached the breakeven point at a sales level of $1,050,000$ units with a sales value of IDR $32$ billion. Variable costs per unit $=$ IDR $300$ thousand, while total fixed costs $=$ IDR $8$ billion.

What is PT DEF's Contribution Margin Percentage?

a$.25\%$

b$.40\%$

c$.53\mathrm{.}33\%$

d$.$ Cannot be calculated due to insufficient data