A company sells wooden chairs at a selling price of IDR $30$ thousand per chair. The purchase cost from the supplier is IDR $16$ thousand per chair. The company gives sales commissions to salespeople of $10\%$ of the amount sold and incurs shipping costs of IDR $1$ thousand per chair.

In order to support its operational activities, the company rents a coworking space with a rental fee of IDR $5$ million per month and other operational costs $($salaries$,$ utilities$)$ of IDR $10$ million per month. The company does not have other costs outside operational activities.

What is the Degree of Operating Leverage if the company has a sales target of $3,000$ units?

a$.1$

b$.1\mathrm{.}67$

c$.1\mathrm{.}89$

d$.2$