Leighton Inc. inventory records for a particular development program show the following at October $31,2020$:

$($Click the icon to view the inventory records.$)$

Leighton uses the perpetual inventory system.

Requirements

Compute cost of goods sold and ending inventory, using each of the following methods:

a$.$ Specific unit cost, with two $$165$ units, three $$175$ units, and four $$185$ units still on hand at the end

b$.$ Weighted$-$average cost

c$.$ First$-$in$,$ first$-$out cost

Which method would be most relevant to producing the highest net income? Why?