Which of the following observations about prime cost is incorrect?

A$.$ Prime cost relers to the ageregate of drect matenal, direct latiour, and direct expenses.

B$.$ Frime cost, pireraly, constives $5005$ to $80\%$ of the fots cost of a product

C$.$ Prme cast is bit the centre of the complation of conversion cast.

$10.$ Prere cost is promary to the cost of s product.