Which of the Following Struct Definitions Is Correct in C $\quad$

Multiple Choice

Which of the following struct definitions is correct in C++?

A) struct studentType
{
$\quad$ int ID;
};
B) struct studentType
{
$\quad$ string name;
$\quad$ int ID;
$\quad$ double gpa;
}
C) int struct studentType
{
$\quad$ ID;
}
D) struct studentType
{
$\quad$ int ID = 1;
};