Waygate's Residential Internet Modem Works Well but Is Sensitive to Power-Line

Multiple Choice

Waygate's residential Internet modem works well but is sensitive to power-line fluctuations. On average, this product hangs up and needs resetting every 200 hours. On average about 45 minutes is needed to reset this product. What is this product's availability?

A)  not in excess of .75
B)  in excess of .75 but not in excess of .8
C)  in excess of .8 but not in excess of .9
D)  in excess of .9 but not in excess of .95
E)  in excess of .95