A. His subordinate is punished by the Army chief.
B. His subordinate is being punished by the Army chief.
C. His subordinate was punished by the Army chief.
D. His subordinate was being punished by the Army chief.
Given sentence is in simple past tense and it is in active voice, we need to change it into passive voice.
Rule :
Subject + (was / were) + V3 + Optional Agents