Refer to the association marked with the number 7 in the preceding diagram. Assume that customers pay

Question:

Refer to the association marked with the number 7 in the preceding diagram. Assume that customers pay for all sales during the month in full at the end of the month. Which of the following is the multiplicity that should be found next to the sales class?
a. 0..*
b. *..*
c. 0..1
d. 1..1
e. 1..*