Who sits on the chair numbered 4 at the end of Turn 3?

Based on the information about the initial positions of Aslam and Chhavi sitting next to each other, while Bashir and Davies have empty chairs on either side of their seats, the possible combinations are,
This has 4 possible combinations.
We are also given that Davies occupies Chair 2 after Turn 1 and Chhavi occupies Chair 7 after Turn 2. We know that the positions of Davies and Chhavi won't be changing after turn 2, as we know that in those turns, only the positions of Aslam and Bashir are being changed in the first 2 turns. Therefore, we can determine that Davies' initial position is chair 2, and Chhavi's initial position is chair 7.
Out of the 4 possible combinations, Davies on chair 2 and Chhavi on chair 7 are only possible in one case, which is,
We now have the initial position, and we are told that all the members are adjacent only after turn 2 and turn 6.
We know that A changed his position in turn 1.
Turn 1: Aslam moves
If A changed his position anticlockwise, he would go to chair 5, and if he changed his position clockwise, he would go to chair 1.
If A ends in chair 5 after turn 1, then it is not possible for all of them to be adjacent to each other after B changes his position in turn 2.
So, A has to end in chair 1 after turn 1, so that B will have a chance in turn 2 for all of them to be adjacent.
Turn 2: Bashir moves
 For all of them to be adjacent after turn 2, B must change his position anticlockwise, and after turn 2, he would end up on chair 3.
Turn 3: Chhavi moves
We are given that Davies occupies chair 4 after turn 5, and for this to happen, chair 4 must be empty and cannot be occupied by anyone who does not move before turn 5. So, in turn 3, C must go anticlockwise and occupy chair 6, as if he goes clockwise, he would occupy chair 4, which must be empty for Davies.
Turn 4: Davies moves
Davies will not move in turn 5, and for him to occupy chair 4 after turn 5, he must occupy it on turn 4. So, D has to go clockwise in turn 4 and must occupy chair 4.
Turn 5: Aslam moves
We know that all of them are again adjacent after turn 6. If A goes clockwise in turn 5, then he will occupy the chair 2, and in that case, it is not possible for them to be adjacent after turn 6 in either of the cases of B going clockwise or anticlockwise.
So, A must go anticlockwise and occupy chair 7 for them to be adjacent after turn 6.
Turn 6: Bashir moves
Now, for them to be adjacent after turn 6, B must go clockwise and must occupy chair 5.
Turn 7: Chavvi moves
We do not have any information to determine whether C went clockwise or anticlockwise. So, both cases are possible after turn 7.
After turn 3, chair 4 is occupied by no one.
Hence, the correct answer is option D.