The practice of taking performance boosting drugs among athletes P : but checking it is not going to be easy Q : is generally conceded to be unfair R : of the detection technology S : for the user is generally one jump ahead The Proper sequence should be:

QPRS
QPSR
RQPS
RQSP

The correct answer is: B. QPSR

The practice of taking performance boosting drugs among athletes is generally conceded to be unfair, but checking it is not going to be easy. This is because the technology for detecting performance-enhancing drugs is constantly evolving, and users are always one step ahead.

Option A: QPRS is incorrect because the sentence “but checking it is not going to be easy” should come after the sentence “The practice of taking performance boosting drugs among athletes is generally conceded to be unfair.”

Option C: RQPS is incorrect because the sentence “for the user is generally one jump ahead” should come after the sentence “of the detection technology.”

Option D: RQSP is incorrect because the sentence “The practice of taking performance boosting drugs among athletes is generally conceded to be unfair” should come before the sentence “but checking it is not going to be easy.”