You will be given a definition of a task first, then some input of the task.
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.

Question: How tall is the rock that "offered a climbing problem" for the 1933 British Mount Everest expedition? Passage:The main party left England by sea on 20 January 1933, stopping at Gibraltar, where the Rock of Gibraltar "offered a climbing problem or two", and Aden. Time at sea was spent discussing the problem of climbing Mount Everest and the establishment of the various camps on its northern side, as well as learning the Nepali language, in which Crawford was proficient. The party alighted at Bombay, where they were assisted by C. E. Boreham, the manager of the Army and Navy Stores. Ruttledge, an India hand, took them on sightseeing tours to Agra and Fatehpur Sikri. Passing through Calcutta, where they were entertained by the Governor of Bengal, Sir John Anderson, the expedition members proceeded to Darjeeling, where Smythe, Greene and Birnie joined them, while Ruttledge went to Siliguri to rendezvous with Shebbeare and discuss transport arrangements. At Darjeeling porters were selected for the march, Ruttledge's Sherpas from his 1932 trip, Nima Dorje and Sanam Topgye, having gone to Sola Khombu to alert prospective applicants to the existence of the British expedition. Llakpar Chedi, Lewa and Nursang were selected as sirdars. In addition, Nima Tendrup, a veteran of many expeditions to Mount Everest, as well as a number of Sherpas who had been on the recent German expeditions to Kangchenjunga, were brought along. Karma Paul, who had been on the 1922 and 1924 British expeditions, was taken as interpreter. All the porters were screened at the Darjeeling hospital, 34 per cent being found to be infected with internal parasites, and then clothed in blue-and-white striped pyjamas and given numbered identity disks.

Output:
b