Please give answer, only answer, to both questions thanks !

The sigma factor in E.coli is required for A. binding of the holoenzyme to promoter DNA sequences. B transcription initiation. C. transcription initiation and elongation. D. transcription initiation, elongation and termination. E. A and B are both correct. F. A and C are both correct. The T loop is found in which cellular structure A. Core promoter sequence. B. Telomere C. Centromere D. DNA replication fork