If total revenue is $$400,000$ and operating income is $$250,000,$ then the operating margin is $\_\_\_\_\_\_\_\_\_\_.$

A$.)$

$37\mathrm{.}50\%$

B$.)$

$62\mathrm{.}50\%$

C$.)$

incalculable without operating expenses data

D$.)$

incalculable without EBIT data