Select the option that represents the letters that, when placed from left to right in the blanks below, will complete the letter series.

_ T U _ R T _ S _ _ W S R T X _

Logic: We have to put each option in the blank space when any option gives us a proper logical series that will be correct option.

From option (a): ​RTUSRX

R T U T R T U S S R W S R T X X (not follows logical pattern)

From option (b): ​RSVRTS

R T U S / R T V S / R T W S / R T X S (follows the logical pattern, the series has followed U, V, W and X remaining letters are same)

From option (c): ​RSVTRR

R T U S R T V S T R W S R T X R (not follows logical pattern)

From option (d): ​RSVRTR

R T U S R T V S R T W S R T X R (not follows logical pattern)

Thus, Option B is the correct answer.