If you buy one pair of uvex clear uvextreme safety eyewear in the winter, the cost is $7.40. but if you buy 10 pairs in a single purchase, the price per pair is reduced to $6.85, a total savings of $5.50. this is an example of a

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.