Correct Answer  Option 3 : SUM()
The correct answer is SUM().
 The SUM function in excel is an inbuilt function that is used to sum numerical values present in a range of cells.
 It is a mathematical formula in excel which can be used by typing =SUM( keyword in the cell where we want the sum to be calculated and then we select the range of cells that are to be added.

The Excel Math Functions perform many of the common mathematical calculations, including basic arithmetic, conditional sums & products, exponents, etc.
 It is used to calculate values based on what is in cells, perform operations on a cell content, fetch values after an operation based on your search criteria, and much more.
 Mathematical Formulas in Excel are used to perform various arithmetic operations like sum, average, count, max, min, etc.
Other functions in Excel.
Commands 
Functions 
IF 
IF function in Excel checks whether a condition is met and returns one value if true and another value if false.

SUM 
Excel automatically enters a formula (that uses the SUM function) to sum the numbers. 
COUNT 
COUNT Function to get the number of entries in a number field that is in a range or array of numbers. 
AVERAGE

To perform the average formula in Excel, enter the values, cells, or range of cells of which you're calculating the average in the format, =AVERAGE (number1, number2, etc.) 
AND 
It is used to check more than one condition at the same time. AND function returns either TRUE or FALSE. 