In this question are given four statements followed by five conclusions, one of which definitely does not logically follow (or is not a possibility of occurrence) from the given statements. That conclusion is your answer.
Note:- You have to take the four given statements to be true even if they seem to be at variance with commonly known facts and then decide which of the given conclusions logically does not follow from the given statements disregarding commonly known facts.
Statements:-
All references are mails.
All mentions are references.
All comments are mentions.
No mail is a declaration.
Conclusions:-
a. No reference is a declaration.
b. All comments are mails.
c. No mention is a declaration.
d. All declarations being comments is a possibility.
e. Atleast some mails are mentions.