The tiger urine odor is exclusively below the tarpaulin. What is the implication of this fact?
a. The tiger urine cannot be detected above the tarpaulin.
b. There must be tigers that frequently urinate in the area below the tarpaulin.
c. The tarpaulin is effective at containing the odor of the tiger urine.
d. The presence of the tarpaulin indicates a deliberate effort to contain the odor of the tiger urine.