Concept:The sentence parts need to be arranged in a logical and grammatically correct order.
Explanation:Start with part Q because it sets the time context: "ever since the COVID-19 pandemic began".
Next comes part S, which introduces what is being calibrated: "calibrating disease-related risk".
Then part P follows naturally: "has become".
Finally, part R completes the sentence: "a fixture of everyday life".
Thus the correct order is Q, S, P, R.
Answer:QSPR (Option A).