Place the following steps for the elongation of bacterial protein biosynthesis in the correct order:

1) gtp is hydrolyzed by elongation factor-tu and the aminoacylated trna moves into the a site.
2) the peptidyl-trna translocates from the a site to the p site.
3) the charged aminoacylated trna and elongation factor-tu are escorted into the a site.
4) the a site is aligned with the mrna codon for the next amino acid.
5) peptide bond formation takes place and the peptidyl chain is transferred to the peptidyl-trna to the aminoacylated trna, in a move catalyzed by peptidyltransferase.
6) the a site now accepts the elongated peptidyl-trna.
7) the previously deacylated trna is released from the e site.

a. 3, 4, 1, 7, 2, 5, 6b. 4, 3, 1, 5, 2, 7, 6c. 4, 3, 2, 1, 5, 7, 6d. 6, 3, 2, 5, 1, 7, 4