Final answer:
The COUNT() function is used to determine the total number of items in a specified range.
Step-by-step explanation:
The function that determines the total number of items in a specified range is the COUNT() function.
This function counts the number of cells in a range that contain numbers, dates, or text.
For example, if you want to count the number of students in a class, you can use the COUNT() function to find the total number of names in a specified range.