Six persons are sitting in a circle. A is facing B, B is to the right of E and left of C. C is to the left of D. F is to the right of A. Now D exchanges his seat with F and E with B. Who will be sitting to the left of D?

Draw a figure on the basis of above given question ,
Bus M is standing at the front and Q is standing at the back end. Bus N stands between M and O. Bus P stands between O and Q.
From figure , Bus O is in the middle of the five.
Sitting arrangement :-

According to question,
We can draw a figure , in which D is on the left of C and B is on the right of E. A is on the right of C and B is on the left of D. If E occupies a corner postion.
As shown in figure , D is sit in the centre .
Sitting sequence :-

Draw a figure on the basis of above given question ,
C is between A and E. B is just to the right of E but left of D. F is not at the right end.
As shown in figure , B and D are to the right of E.
Sitting arrangement :-

According to question,
We can draw a figure , in which C is between A and E. B is just to the right of E but left of D. F is not at the right end.
From it is clear that , D is at the right end .
Sitting arrangement :-

According to question,
We can draw a figure , in which M is on the right of N and P is on the left of O .
From it is clear that ,N and P are partners.
Sitting arrangement :-

According to question,
We can draw a figure , in which E and F are in the centre and A and B are at the ends. C is sitting on the-left of A.
From given figure it is clear that , D is sitting on the right of B.
Sitting arrangement :-

According to question,
We can draw a figure , in which C is to the left of D, F is between A and E, and E is between F and D.
From it is clear that , E is to the left of F.
Sitting sequence :-

As per Question,
A, B, C, D, E, F, G and H are setting in a row facing North.
A is fourth to the right of E.
E -- 1 -- 2 -- 3 -- A
H is fourth to the left of D.
H -- 1 -- 2 -- 3 -- D
C and F, which are not at the ends, are neighbors of B and E, respectively.
-- --C -- B -- -- -- F -- E-- --
H is next to the left of A and A is the neighbor of B.
-- -- --H--A --B -- --
The order of sittings of eight persons which satisfies all the above condition will be as in below figure.
E--F--G--H--A--B--C--D

It is clear from the above order that F is next to the right of E.

As per Question,
A, B, C, D, E, F, G and H are setting in a row facing North.
A is fourth to the right of E.
E -- 1 -- 2 -- 3 -- A
H is fourth to the left of D.
H -- 1 -- 2 -- 3 -- D
C and F, which are not at the ends, are neighbors of B and E, respectively.
-- --C -- B -- -- -- F -- E-- --
H is next to the left of A and A is the neighbor of B.
-- -- --H--A --B -- --
The order of sittings of eight persons which satisfies all the above condition will be as in below figure.
E--F--G--H--A--B--C--D

Statement (d) is wrong because C is next to the right of B.

As per Question,
A, B, C, D, E, F, G and H are setting in a row facing North.
A is fourth to the right of E.
E -- 1 -- 2 -- 3 -- A
H is fourth to the left of D.
H -- 1 -- 2 -- 3 -- D
C and F, which are not at the ends, are neighbors of B and E, respectively.
-- --C -- B -- -- -- F -- E-- --
H is next to the left of A and A is the neighbor of B.
-- -- --H--A --B -- --
The order of sittings of eight persons which satisfies all the above condition will be as in below figure.
E--F--G--H--A--B--C--D
Because D is to the extreme right hence, has only one neighbor C.