mrinal2100 wrote:see the attachment
answer-
D

The answers is between A and D.
For answering you should be knowing the difference between sufficiency and necessary Also necessary and sufficient indicators.
Now the stimulus says:
reptiles are incapable of making alterations in behavior---------->>>>incapable of complex reasoning .
We can say it as
capable of complex reasoning ---------------->>>> capable of making alterations in behavior.
Now A says:
Major changes in behavior -------->>>>>>capable of complex reasoning (this makes our necessary statement as sufficient and our sufficient statement as necessary, note Only if refers a necessary condition)
refer to D
capable of complex reasoning ---------->>>>>>able to make changes (This matches our conclusion. Hence correct .)