Given a paragraph from a Wikipedia article about some topic, and a question related to the topic, determine whether the question is answerable from the paragraph. If the question is answerable, answer "True", otherwise, answer "False".

Popper won many awards and honours in his field, including the Lippincott Award of the American Political Science Association, the Sonning Prize, the Otto Hahn Peace Medal of the United Nations Association of Germany in Berlin and fellowships in the Royal Society, British Academy, London School of Economics, King's College London, Darwin College, Cambridge, and Charles University, Prague. Austria awarded him the Grand Decoration of Honour in Gold for Services to the Republic of Austria in 1986, and the Federal Republic of Germany its Grand Cross with Star and Sash of the Order of Merit, and the peace class of the Order Pour le Mérite. He received the Humanist Laureate Award from the International Academy of Humanism. He was knighted by Queen Elizabeth II in 1965, and was elected a Fellow of the Royal Society in 1976. He was invested with the Insignia of a Companion of Honour in 1982. Question: For what reason was Popper able to call himself "Sir?"
True