How do you declare a multidimensional array with 3 rows and 4 columns in C++?

What is the correct way to declare a one-dimensional array in C++?

A. int* arr = new int[size];

B. int[] arr = new int[size];

C. int arr = new int[size];

D. int arr[size];

How do you access the third element of an array named 'arr' in C++?

A. arr(3)

B. arr[3]

C. arr[2]

D. arr(2)

What is the size of the following array declaration in C++: char str[10];?

A. 11

B. 10

C. Depends on the length of the string assigned to 'str'

D. None of these

What is the purpose of the 'strlen()' function in C++?

A. Concatenates two strings

B. Compares two strings

C. Returns the length of a null-terminated string

D. Copies a string to another string