Statement :
A major river in the city was reduced to a polluted and dirty canal after tonnes of sewage made way into it over the years.
Course of action :
I All those who dumped garbage and sewage into the river should be penalized.
II. The Government should modify the sewage system and find an alternate way to dump the city's waste.

C is the daughter-in-law of A who is the grandmother of F means C is the mother of F But F is the son of B. 

So, B is C's husband. But C, the lawyer is married to the Doctor So, B is the Doctor. F, the Accountant, will be the son of B and C, E is the unmarried Engineer. 

So, the other named couple can be that of grandmother of F. i.e, A and D But D, the Salesman, is married to the Lady Teacher. So, D, the Salesman, is the grandfather of F, father of B and the husband of A, the Lady Teacher. 

Clearly, B is the Doctor. 

D is father of A and grandfather of F. So, A is father of F. 

Thus, D and A are the two fathers. C is the sister of F So, C is the daughter of A. 

Since there is only one mother, it is evident that E is the wife of A and hence the mother of C and F. 

So, B is brother of A There are three brothers. So, F is the brother of C. 

A, the father. is male B, the brother, is male, C, the sister, is female D, the grand-father, is male, E, the mother, is female F, the brother, is male. 

So, there are four males. 

Here the P is the wife of Q who is brother of T who is daughter of U.

That implies P is wife of U's son Q => U is father-in-law of P.