Mcmurphy corporation produces a part that is used in the manufacture of one of its products. the costs associated with the production of 12,000 units of this part are as follows: direct materials $86,000 direct labor 126,000 variable factory overhead 58,000 fixed factory overhead 138,000 total costs $408,000 of the fixed factory overhead costs, $55,000 is avoidable. conners company has offered to sell 12,000 units of the same part to mcmurphy corporation for $41 per unit. assuming there is no other use for the facilities, mcmurphy should a) make the part, as this would save $16 per unit b) buy the part, as this would save $16 per unit c) buy the part, as this would save the company $192,000 d) make the part, as this would save $14 per unit if mcmurphy had the opportunity to use the facility to make a different product that would have a total contribution margin of $168,000, mcmurphy should: