$86.$ A company has recorded the following in the three most recent periods:

Month

July August September

Total cost of production $

$406,000346,000368,000$

Volume of production Units

$24,00018,00020,000$

Compute the estimated cost of production for October if the volume of production is expected to be $22,000$ units. a$.$ $$386,000.$

b$.$ $$387,000.$ c$.$ $$388,000.$ d$.$ $$400,000.$