Which fruit has the lowest unit price? A.

2.5 pounds of grapes for $4.19
B.

4 pounds of apples for $5.49
C.

5 pounds of oranges for $6.99
D.

6.5 pounds of strawberries for $9.59

A unit is a measure of ratio between two quantities. In this instance, the unit is a pound. The ratio you need to take is the price of each fruit and divide it by the number of pounds each fruit has to get a price per pound. See below for solution.

Step-by-step explanation:

A. 4.19 dollars / 2.5 pounds = 1.676 dollars / pound

B. 5.49 dollars / 4 pounds = 1.3725 dollars / pound

C. 6.99 dollars / 5 pounds = 1.398 dollars / pound

D. 9.59 dollars / 6.5 pounds = 1.475 dollars / pound

The lowest is B, the apples.