Teacher:In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it, i.e., the proper nouns in the passage. Your job is to determine whether information from more than one term is needed to answer the question. Indicate your choice as 'a' for Yes or 'b' for No.
Teacher: Now, understand the problem? Solve this instance: Question: How many years had the Sea Harrier been in service? Passage:The aircraft carrier's major instrument of power projection is the carrier air group. The larger the air group, the more tasks it can perform. The Invincible class, because of its small size, had only a limited capacity, and was only capable of operating STOVL aircraft, the Harrier GR7/GR9. In 2006 the Sea Harrier was withdrawn from service. This saw the front line Sea Harrier squadron of the Fleet Air Arm converting to the Harrier GR9, as part of the evolution of the Joint Force Harrier concept. The Harrier's eventual replacement in both the RAF and the FAA is the F-35 Lightning II Joint Combat Aircraft. The F-35 will be a significant improvement over the Harrier, in terms of speed, range and weapon load. The UK had plans to order 138 F-35Bs for the Royal Navy and Royal Air Force. The financial crisis led to the decision taken in the Strategic Defence and Security Review 2010 to immediately withdraw the Harrier GR9 force in late 2010 along with HMS Ark Royal, to reduce the total number of F-35s planned for purchase by the UK, and to purchase the F-35C CATOBAR version rather than the STOVL F-35B. By May 2012, the government had decided to purchase the short-take off version, the F-35B instead. In July 2012, the Secretary of State for Defence stated that an initial 48 F-35Bs will be purchased to equip the carrier fleet. In September 2013, it was announced that the second JSF squadron would be the Fleet Air Arm's 809 NAS. Chancellor George Osborne announced on 22 November 2015 that the UK will have 24 F-35Bs on its two new carriers by 2023. The Strategic Defence and Security Review 2015 also confirmed that the United Kingdom will buy 138 F-35s over the life of the program. On 20 May 2016, it was reported that the UK would field four frontline squadrons as part of its Lightning Force, including 809 NAS and 617 Squadron, plus an RAF-numbered Operational Conversion Unit (later 207 Sqn) and 17(R) Squadron as the Operational Evaluation Squadron. 809 NAS will stand up in April 2023.

Student:
b