The data below shows the number of kilowatt hours of electricity used by the tenants of a small apartment building in a given month. what is a cumulative table that represents the data?

80 85 86 90 96 75 66 70

99 65 70 99 70 73 64 92

72 81 88 91 93 69 77 82

a: kilowatt hours frequency cumulative frequency
60-69 7 24
70-79 4 24
80-89 5 24
90-99 6 24

b: kilowatt hours frequency cumulative frequency
60-69 4 4
70-79 6 10
80-89 7 17
90-99 7 24

c: kilowatt hours frequency cumulative frequency
60-69 4 4
70-79 7 11
80-89 6 17
90-99 7 24

d: kilowatt hours frequency cumulative frequency
60-69 7 7
70-79 4 11
80-89 7 18
90-99 6 24