Select the combination of letters that when sequentially placed from left to right in the blanks of the given series, will complete the series.
a_cd_cba_bcddc_a
1
adcb
2
aaba
3
babd
4
bdab
Select the combination of letters that when sequentially placed from left to right in the blanks of the given series, will complete the series.
a_cd_cba_bcddc_a