Concept:Arrange the six persons in a row based on given conditions.
Explanation:Let positions be 1 (leftmost) to 6 (rightmost).
Given: D is 3rd left of E, so E at
p, D at
p−3. B is immediate right of E, so B at
p+1.
C is between A and E. Since B is at
p+1, C cannot be there, so C is at
p−1 and A at
p−2.
Thus positions: D at
p−3, A at
p−2, C at
p−1, E at
p, B at
p+1.
p must be
≥4 and
≤5. Try
p=4: D at 1 (end) violates "D not at end".
p=5: D at 2 (not end), remaining position 1 for F. F at left end, not right end, valid.
Final left-to-right: 1-F, 2-D, 3-A, 4-C, 5-E, 6-B.
Left of D is the person at position 1, i.e., F.
Answer:B. F