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: What is the location of the city where Markos first appears in the beginning of the 15th century? Passage:He first appears in Constantinople in 1401, qualified as an oikeios of the emperor. In 1417 he was possibly sent on a diplomatic mission to the Venetians in the Morea. In 1422 and again in 1429 he was sent by Emperor John VIII Palaiologos as an envoy to the Ottoman Sultan Murad II. At the time he had the relatively lowly rank of protovestiarites, but was quickly promoted to protostrator and then to the senior rank of megas stratopedarches, which he held already during his mission in 1430 to Pope Martin V. During his return from the mission to the Pope, on orders from the Emperor, he raised Thomas Palaiologos to the rank of Despot in the Morea. He led two more missions abroad, one in 1433 to Pope Eugene IV, and one in 1438 to Venice.


b