Select the best choice and write the letter for your choice in the box provided In contrast to pointers, a reference in C++: a. must be initialized b. cannot have its value displayed c. is automatically dereferenced when used d. none of the above e. all of the above After executing the code fragment below, what is the result? int var; int& vr var var 3 Cout vr; a. a runtime error occurs because vr is not initialized b. the value 0 is printed c. the value 3 is printed d. runtime error occurs because vr has not been accessed e. this code fragment will not compile The difference between accessing an entry in an array and accessing an entry in a vector is a. there is no difference b. an entry is checked to see if it is in the vector before adding it c. adding an item to the vector takes extra time but with an array memory is automatically expanded to grow the array d. finding an element in a vector is faster e. none of the above