Consider a small circular linked list. How to detect the presence of cycles in this list effectively?

[answerhappygod]

a) Keep one node as head and traverse another temp node till the end to check if its ‘next points to head
b) Have fast and slow pointers with the fast pointer advancing two nodes at a time and slow pointer advancing by one node at a time
c) Cannot determine, you have to pre-define if the list contains cycles
d) Circular linked list itself represents a cycle. So no new cycles cannot be generated