Step 1: Find the subject and verb.
R ("the instructions") is the subject, and Q ("were detailed, yet") contains the main verb. These naturally pair at the start.
Step 2: Build the contrasting clause.
The word "yet" introduces a contrast. S ("some participants misunderstood") begins the contrasting clause, and P ("them and confused") completes it, with "them" referring back to "the instructions."
Step 3: Confirm the order.
RQSP gives: "the instructions were detailed, yet some participants misunderstood them and confused." \[ \boxed{\text{RQSP}} \]