We have a deleteNode function which will delete the node with data value val Assume the nodes' data values are all different, and there always exists the node to delete). struct Node int data; Node* next; t: int deleteNode(int val) Node *pres head; Node *prev NULL ; while(pres->data != val) prev = pres; pres-pres->next; prev->next pres->next; = return 1 What's wrong with the function? (select all that apply) Select one or more: a. nothing wrong b. function doesn't check edge case when head is NULL c. will have problems when head node is the expected node to delete d. function doesn't free the space of the node to delete after adjusting prev- next pointer