I have a question just to verify myself with some graph theory questions as I have forgotten most of my graph theory since highschool. This is the exercise i found from my old high school archives:
This is what i think the answers are:
The first three are all Eulerian Circuits, then Hamiltonian Circuit then Hamiltonian Path.
I basically get like the general idea behind what circuits paths and are but it is so confusing when I have to distinguish the different kinds like I have no problem with like proofs to graph theory results but these kind of questions confuse me so much.
Could anyone help me check my answers?
( I cannot seem to find the homework and exercises tag).

According to what I understood, the first four are all returning to where they begun, so they are all circuits.
$a-$Eulerian Circuit
$b-$Hamiltonian Circuit
$c-$Eulerian Circuit
$d-$Hamiltonian Circuit
$e-$Hamiltonian Path