'P' will be the first part of the given sequence as 'requesting a few days of grace' is used in relation to 'asking me to return' in the opening part. 'R' will follow next as the transition word 'then' shows that after having booked the return passage, packing and attending sundry matters, he went to the bank for further proceedings. 'Q' will follow next as it states the next thing done by him, that is, visit to the laundry. 'S' will come next as the pronoun 'it' is used in the context of 'laundry' mentioned in 'Q'. Hence, PRQS is the correct sequence. Thus, option (b) is correct.