Each option needs to be tested against one question: did this body actually carry out a reform of criminal law, or did it merely study a related but broader subject?
This is a case of matching a specific piece of criticism to the person who is on record for making it, so the options can be worked through by elimination.
To find the odd one out, each option can be checked against what "classical principles of criminal law" actually protect, namely the presumption of innocence, the prosecution's burden of proof and narrowly drawn offences.
The four options can be sorted by whether they both reach the right conclusion and give the right reason for it.
The options can be tested against what a sentencing court is actually required to weigh under settled doctrine.
Each option can be checked directly against what the three cited judgments actually say about death sentencing in India.
Comparing the five Machhi Singh categories against the Bachan Singh test shows which side of the crime-criminal balance survived and which fell away.
The quotation can be matched to its author by checking which of the four had the vantage point to compare the IPC's practical record against English, French and German law.
The four options can be measured against whether they align with or contradict Fitzgerald's warning about conspiracy law being pressed beyond its true limits.
Each theory of punishment can be tested against what a rights-respecting revision of criminal law is expected to prioritise.