‘Q’ will be the first part of the given sequence as it describes the after events when Ross had sent an account of his work to Manson, that is, he described the results to the British Medical Association. ‘P’ will come next as the pronoun ‘they’ refers to ‘Ross’s results’. ‘S’ will come next as it tells the effect of Ross’s results which has created sensations, that is, the audience appreciated it. ‘R’ will follow it because it defines that after hearing about his results president of Royal Society paid a visit to him and as a result he was elected a fellow in the Society (given in S6.) Hence, QPSR is the right sequence. Thus, option (c) is correct.