Detailed Instructions: 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.
Q: Question: What year was the city founded where the German Sixth Army was encircled? Passage:As the German Sixth Army was encircled in Stalingrad, the Red Army undertook a series of wider attacks against the rest of Army Group South. These culminated on 2 January 1943 when the Red Army launched Operation Star and Operation Gallop, which between January and early February broke German defenses and led to the Soviet recapture of Kharkov, Belgorod, Kursk, as well as Voroshilovgrad and Izium. The Soviet victories caused participating Soviet units to over-extend themselves, though this was largely due to Manstein's strategy of controlled retreat towards the Dneiper. Freed on 2 February by the surrender of the German Sixth Army, the Red Army's Central Front turned its attention west and on 25 February expanded its offensive against both Army Group South and Army Group Center. Months of continuous operations had taken a heavy toll on the Soviet forces and some divisions were reduced to 1,0002,000 combat effective soldiers. On 19 February, Field Marshal Erich von Manstein launched his Kharkov counterstrike, using the fresh II SS Panzer Corps and two panzer armies. Manstein benefited greatly from the massive air support of Field Marshal Wolfram von Richthofen's Luftflotte 4, whose 1,214 aircraft flew over 1,000 sorties per day from 20 February to 15 March to support the German Army, a level of airpower equal to that during the Case Blue strategic offensive a year earlier.

A:
a