Answer:
Option: b is the correct answer.
b. Positive relationship; as the size of the household increases, the amount of the water bill also increases.
Step-by-step explanation:
As the size of the household increases i..e the number of members increases the water usage would also increase and hence the bill of the water increases.
OR
Decrease in household would lead to the decrease in the water bills.
Hence, the correct relationship that describes the size of household and amount of water bill is:
Positive relationship.
Hence, option: b is the correct answer.