Detailed Instructions: In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it. Your job is to determine which sentence(s) from the passage can be used to search for further information needed to answer the question.
Problem:Question: How many groups were stationed at RAAF Station Pearce in August 1940 when Charlesworth was in command? Passage:As part of the RAAF's reorganisation following the outbreak of World War II in September 1939, No.2 Group was formed in Sydney on 20November; Charlesworth was appointed its Senior Air Staff Officer (SASO). He continued to serve in this position when the group was re-formed as Central Area in March 1940. Posted to Western Australia to take command of RAAF Station Pearce in August, he was promoted to temporary group captain on 1September 1940. He became Senior Administration Officer at the newly established Western Area, Perth, in January the following year. In September 1942, Charlesworth took over No.2 Bombing and Gunnery School in Sale, Victoria. He handed over to Group Captain Charles "Moth" Eaton in August 1943, before briefly taking charge of RAAF Headquarters Forward Echelon in Brisbane. Charlesworth was appointed Air Officer Commanding (AOC) Eastern Area, headquartered at Bradfield Park, Sydney, in December 1943. Eastern Area was responsible for maritime patrol and anti-submarine warfare off the coast of New South Wales and southern Queensland. Japanese submarine activity had decreased in the months prior to Charlesworth taking command, and he was concerned that Allied ships were becoming complacent. He observed "a general slackening off in procedure; ships are seldom where they should be, and a minority of merchant ships identify themselves to aircraft". The RAAF's patrols had also settled into a predictable pattern that would have been easy for an observant submarine captain to avoid.

Solution:
Posted to Western Australia to take command of RAAF Station Pearce in August, he was promoted to temporary group captain on 1September 1940