UPSC CDS English Ordering of Words in a Sentence Part 1 Questions

‘Regards to’ is a phrase and it forms a logical pair of SR. S grammatically cannot follow Q as it is followed by R; hence, it follows P because grammatically S cannot be the first part of the sentence as it starts from conjunction/connector. Among the given options, only (d) has a chronological order of PSR. Thus, it is clear that the correct option is (d).