Question

based on this excerpt, fans that use frank fishs blade design
a increase air flow but use twice as much power.
b save energy but produce a lot of dust.
c use more energy and move less air.
d achieve better cooling and energy savings.
whalepower has also licensed this design to another company that is using it to build industrial fans for warehouses and barns. the fans use half the number of blades, move 25 percent more air and use 25 percent less power than fans with conventional blades turning at the same speed.

Explanation:

The text states that fans using Frank Fish's blade design move 25 percent more air and use 25 percent less power than conventional - bladed fans at the same speed. Moving more air can lead to better cooling, and using less power means energy savings.

Answer:

D. achieve better cooling and energy savings