In the following question, which one set of letters when sequentially placed at the gaps in the given letter series shall complete it?
a_b_a_c_a_bc
1). bccbb
2). bcbca
3). cabca
4). acbcb
1. Choose the correct order of the given alternative : a _ bc _ c _ abb _ bca _
2. Choose the correct order of the given alternative : c _ ac _ aa _ aa _ bc _ bcc
5. Choose the correct order of the given alternative : a _ bc _ a _ bcda _ ccd _ bcd _
6. Choose the correct order of the given alternative : adb _ ac _ da _ cddcb _ dbc _ cbda
7. Choose the correct order of the given alternative : ccbab _ caa _ bccc _ a _
9. Choose the correct order of the given alternative : _ stt _ tt _ tts _