The correct option is A When Macdonald reached Inverary, the sheriff was away celebrating Hogmanay
Option A is INCORRECT because the sheriff was NOT preparing for an attack on the Highland Clans.
Option B is CORRECT because when MacDonald reached Inverary, the sheriff was away celebrating Hogmanay, which is the Scottish word for the last day of the year and is synonymous with celebration of the New Year in the Scottish manner.
Option C is INCORRECT because when MacDonald reached Inverary, the sheriff was alive and was celebrating Hogmanay.
Option D is INCORRECT because option B is correct.