C Switch Cases

Question

I was taking an online quiz based on the C++ switch statement. 

I came across a question, and while I have a good knowledge of how switch statements function, this particular question made no sense to me. 

Could you please explain?

Why is the answer D and not C? Is Case 2: the default case or what?

Answer 1

This is how the code works.

Because x equals zero, the command cout"Zero"; is performed.

Because there is no break, the second case gets executed: cout<<"Hello World";

They are written as a single word since cout<<"something"; does not add a newline after printing.