Put suitable prepositions

There are at least two and probably three mistakes in this exercise. (height, joining? family system (article)) Can you check the original again? Kind regards, Michael

It's the height of selfishness of man to deny the advantage hidden in joint family system for a complete happy life in today's world.

"for man" is better.

"hidden in joint family system" is wrong.

We need clarification from the questioner before we take this further, in my view.

I think it should be like to deny the hidden advantages of joint family system

It was height and joint.

It was height and joint

In that case, the person who set the exercise has some problems with the English language, and should have asked for help before giving it to students. Sorry to give you this bad news.

How it is possible this question is belong to our last year paper.

I think it should be like to .........................to deny hidden advantages of joint family ..............................

I've looked at this again. After adding in your corrections, the only remaining problems are:

a) system" is a countable word and so the paper should have had the word "the" before "joint".
b) there should be a comma or "and" between "complete" and "happy".

It is the height of selfishness for man to deny the advantage hidden in / within the j