DRDO Multi tasking staff Model paper 2

Direction: Read the following passage and answer the questions that follow:
The following graph shows the runs scored at the end of the six overs in a T - 20 match.
1st‌and‌6th over was bowled by bowler A, 2nd‌and‌4th over was bowled by B, 3rd over was bowled by C and the 5th over was bowled by D.

Question:
If no player took more than one wicket and all the wickets fell in simultaneous overs, then in which of the over the wicket did not fell?