Select the combination of letters that when sequentially placed in the blanks of the given letter series will complete the series.
T _ R _ _ S _ D T _ R D _ S _ D
1
D S T R T T R
2
S D T D S T T
3
S D T R S T R
4
S T S R R T R
Select the combination of letters that when sequentially placed in the blanks of the given letter series will complete the series.
T _ R _ _ S _ D T _ R D _ S _ D