In a singly linked list L with more than three nodes, a pointer p points to a node that is guaranteed to be neither the first nor the last node. What are the purposes of the following code blocks $(15\%)?$

a$.$

$q=$ L$->$next$->$next;

$q$ data $=q$ next $$ data;

q$->$next $=$ q$->$next$->$next;

b$.$

$q=L$;

$t=p$ data;

$p$ data$==q$ data;

$q$ data $=t$;

c$.$