Read the statement and answer the question. 'Whenever the price of diesel rises, transport fares in Lagos rise within a week. Transport fares in Lagos did not rise last month.' Which of the following is a valid conclusion?

A rise in diesel price is said to be always followed by a fare rise within a week. Since fares did not rise, there can have been no diesel price rise in the preceding week. The statement does not allow the conclusion that the price fell, only that it did not rise, and the claim about transporters absorbing costs contradicts the rule given. Nothing supports a prediction about this month.