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

T _ _ r S S_ T T r _ _ S u T T r r_ _ u

T r u r S S S

By using all options one by one . We find that only option 1 makes a repeated same series .

T _ _ r S S_ T T r _ _ S u T T r r_ _ u