The correct answer is option 4: S P Q R.
The original sentence is:
"A sell-off as US Treasury yields surged to multi-year highs on robust economic data. Global markets also witnessed."
In this sentence, there are two parts that need to be rearranged: the first part talks about a sell-off due to US Treasury yields surging, and the second part mentions that global markets also witnessed something.
By rearranging the given sequences, we can form the correct sentence:
"S" represents the first part of the sentence, mentioning the sell-off as US Treasury yields surged to multi-year highs on robust economic data.
"P" represents the second part of the sentence, which states that global markets also witnessed something.
"Q" comes after "S" because it provides additional information about the sell-off and yields.
"R" is placed at the end because it completes the second part of the sentence, stating that global markets also witnessed.