Definition: In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as `a` for Yes or `b` for No.
Input: Question: How old was Earl Spencer during the year that Alexander Ross went with him to Vienna on a special mission? Passage:Lieutenant Ross became captain on 30 May, and served with distinction throughout the American war of independence. He was aide-de-camp to Lord Cornwallis and was sent home by him with the despatches of the Battle of Camden on 16 Aug. 1780. He was made major in the 45th Regiment of Foot on 25 October 1780. He represented Lord Cornwallis as commissioner in arranging the details of the surrender of Yorktown. In May 1782 he was sent to Paris to arrange for the exchange of Lord Cornwallis, which was only effected by the peace of 20 January 1783. In August 1783 Ross was appointed deputy adjutant-general in Scotland, with the rank of lieutenant-colonel, and he served in a similar capacity in India under Lord Cornwallis. He became colonel on 12 October 1793. In August 1794 he went with Earl Spencer and Thomas Grenville to Vienna on a special mission to arrange that Lord Cornwallis should command the allies against the French. Their efforts were unsuccessful. He accompanied Lord Cornwallis as major-general to Warley camp in April 1795, and two months later was nominated Surveyor-General of the Ordnance in succession to George Cranfield Berkeley.


b