What is the practice to get the sum of all order line totals on the order header?

Universal Container use a simple order Management app. On the Order Lines, the order line total is calculated by multiplying the item price with the quantity ordered. There is a Master-Detail relationship between the Order and the Order Lines object.

What is the practice to get the sum of all order line totals on the order header?
A . Roll-Up Summary Field
B . Apex Trigger
C . Process Builder
D . Declarative Roll-Up Summaries App

View Answer

Answer: A