The line that most probably contains a commentary on the poet's own era is: e) line 22
What is the line?
This question is drawn from the poem, "Paradise Lost" by John Milton. John Milton lived in an era known as the Puritan Age. In line 22 of his poem, we read; "So since into his Church lewd hirelings climb." The Puritan Age was characterized by a prevalence of religion and the pious standards of the church.
When Milton made a reference to lewd hirelings climbing into the church, he was most likely talking about the paid clergy who mounted the church's pulpits and did not preach the truth. So, the idea being referenced in this commentary is the Puritan Era.