Hey vipulgoyal,

The assumption negation technique works really well here to get you to correct answer A. I know that you tried it and still fell for E, but I think that if you break the argument down correctly and then negate A, it becomes pretty easy.

The first sentence defines what a desire for praise is, and in the scope of the argument is context. It becomes relevant in answer choice A only for inferring that the answer choice is discussing a desire for praise, and therefore linking it to the conclusion. The beginning part of the second sentence is the one premise -> People merit praise only for those actions motivated by a desire to help others. And then the second part of the second sentence is the conclusion -> A person who aids others primarily out of a desire for praise therefore does not deserve praise for that aid.

Attention to detail and wording is very important in critical reasoning questions. So let's look at the argument with answer choice A negated and inserted in as a premise, and we will see it fall apart:

Premise) People merit praise only for those actions motivated by a desire to help others.
Premise) An action that is motivate by a desire for praise CAN also be motivated by a desire to help others
Conclusion) A person who aids others primarily out of a desire for praise therefore does not deserve praise for that aid.

This is clearly wrong, because the second premise states that both are possible. Note that in the first premise there is no required quantity given: peoples' motivations do not have to be over 50% driven by a pure desire to help others in order to merit praise.

E is discussing whether it is the motives or the consequences of an action that determine whether one deserves praise for that action. But the way that an action merits praise is already covered in the premise, and premises are facts, so E is not relevant. It is providing already known information.

I hope this helps!