Option 1 -> Commanding means giving orders authoritatively, which directly matches the assertive, authoritative nature of "peremptory."
Option 2 -> Successive refers to things following in sequence or order, unrelated to the meaning of peremptory.
Option 3 -> Remorseful means feeling regret or guilt, which is opposite to the confident, dictatorial tone of peremptory.
Option 4 -> Enduring means lasting or continuing over time, which doesn't relate to peremptory's meaning.
Hence, Option 1: Commanding -> "Peremptory" describes a manner that is authoritative, dictatorial, and allows no refusal or contradiction, making "commanding" the most appropriate synonym -> correct