How should the developer use AMPscript to generate the total?

A developer wants to aggregate monthly energy usage data over a four month period for each subscriber within an email. The monthly usage values are stored in variables for each month in the following way:

How should the developer use AMPscript to generate the total?
A . SET @total – (@jan – 3fet – @mar @apr>
B. SET @total = AZD((@jan @feb) @mar) @apr)
C. SET @total – ADD(@jan,ADD(@feb,ADD(@mar,@apr)))
D. SET @total = (ADD(@jan,@feb), ADD(@mar, @apr))

View Answer

Answer: C