Please answer all questions with explaination. There's only $1$ correct answer for each question. Will give upvote.

$1.$ What happens if you take the address of a pointer variable with the & operator?

A: It's already a memory address, so you get the same address again.

B: You get the memory address of that pointer variable; it has a memory address too.

C: Your program is likely to crash, since you're referencing memory that was allocated in a stack frame for a function that has already returned.

D: You're emulating pass$-$by$-$value.

$2.$Which of these things can you not have as a field in a struct?

A: A pointer to memory on the stack.

B: A function pointer.

C: A field that is a struct of the same type as the struct itself.

D: A floating point number, since floating point math is notoriously inexact.

$3.$ Which of these are true of breadth$-$first search?

A: Breadth$-$first search keeps its set of previously visited nodes in a stack.

B: Breadth$-$first search is guaranteed to have the shortest possible run$-$time in finding a path, if one exists.

C: Breadth$-$first search only works on directed graphs; for an undirected graph, you have to use depth$-$first search.

D: Breadth$-$first search is guaranteed to find a shortest path in terms of total number of hops in your graph.