The easiest approach was not highly mathematical actually, although I wasted my 5mins initially but when I looked closely the answer came out in 20 sec, so here it goes ...

firstly 100% of ticket sales yield ----------------------------> 120% of total production cost
then the say they sold all but 5% of the tickets, which means 95% sale actually happened -------------------> X% of total production cost (which is what we need to find)
Since if they would have sold all the tickets their total revenue would have been ------------------> 120% (as given)
as they sold only 95%, which tells they made 95% of 120% of the revenue ------------------> so since 10% of 120% is 12%, so 5% of 120% would be 6% => so that means 95% of 120% => 120% - 6% = 114%, so profit slipped from 20% to 14% due to the reduced tickets sale ...
Hence Answer is E) 14%