The results of an analysis, on the makeup of garbage, done by the environmental protection agency was published in 1990. some of the results are given in the following table, which for various years gives the number of pounds per person per day of various types of waste materials.

waste materials
1960
1970
1980
1988
glass
0.20
0.34
0.36
0.28
plastics
0.01
0.08
0.19
0.32
metals
0.32
0.38
0.35
0.34
paper
0.91
1.19
1.32
1.60

for metal, calculate the average rate of change between 1980 and 1988. then interpret what this value means.
a.
from 1980 to 1988, the number of pounds of metal per person per day decreased by 0.00125 per year.
c.
from 1980 to 1988, the number of pounds of metal per person per day decreased by 0.125 per year.
b.
from 1980 to 1988, the number of pounds of metal per person per day decreased by 0.071 per year.
d.
from 1980 to 1988, the number of pounds of metal per person per day increased by 0.01 per year.