A possible ranking is 1, 3;
B The possible rankings are 2, 3 and 4;
C The possible ranking is 1, 5;
D the possible ranking is 5;
E The possible rankings are 2, 4.
Because every ranking was guessed right, so:
The fifth place is d.
So 1 is: C.
So the third place is: a.
The remaining 2 and 4 are B and E respectively.
If you add a condition to the question, everyone will guess at least one place correctly.
Then according to what E said, we can know that B is not the fourth, so B is the second.
So e is the fourth.
Namely: CBAED