Dartmouth Company produces a single product with a price of $11, variable cost per unit of $4, and total fixed cost of $9,400. The variable cost ratio and the contribution margin ratio for Dartmouth, rounded to the nearest whole number, are Oa. 36% and 36% respectively Ob. 64% and 36% respectively Oc. 64% and 64% respectarely Od. 36% and 64% respectively Oe. The contribution margin ratio cannot be determined from the information given