In linked list implementation of a queue, the last inserted node is always pointed by 'rear' and the first node is always pointed by 'front'.
Example:-
In above example, the last inserted node is 50 and it is pointed by 'rear' and the first inserted node is 10 and it is pointed by 'front'. The order of elements inserted is 10, 15, 22 and 50.
Hence,Option(C)only rear pointer changes.
Reference:-http://btechsmartclass.com/DS/U2_T9.html