b$.$ Indicate the effect of each of the following independent events on lines CC$,$ OR$,$ and the break$-$even point:

Line CC Line OR Break$-$Even Point

$1.$ A decrease in fixed costs

$2.$ An increase in unit selling price

$3.$ An increase in variable costs per unit

$4.$ An incrase in fixed costs and a decrease in the unit selling price

$5.$ A decrease in fixed costs and a decrease in the unit variable costs