I need detailed line by line steps on how to solve, and an explanation of the concepts, be ready for follow up questions on your answers :

Natarajan Inc, had the following operating segments, with the indicated amounts of segment revenues and segment expenses :

Segment A : External Revenues : $7,500,000, Intersegment Sales : $600,000 Segment Expenses : $6,300,000

Segment B : External Revenues : $2,900,000 Intersegment Sales : $1,000,000 Segment Expenses : $4,300,000

Segment C : External Revenues : $700,000 Intersegment Sales : $1,300,000 Segment Expenses : $2,200,000

Segment D : External Revenues : $4,000,000 Intersegment Sales : $250,000 Segment Expenses : $4,100,000

Segment E : External Revenues : $1,600,000 Intersegment Sales : $800,000 Segment Expenses : $2,700,000

Question : According to the revenue test, which segments would require disaggregation?

Answer was A, B, D ,E but I need detailed help with steps as to how.