What combination of automation tools should LenoxSoft use to achieve this?

LenoxSoft has had a Product Interest form live on their website for the past 3 months. They would like to make sure that, moving forward, every time the form is submitted, a custom field is updated. They also want to update that custom field for anyone who has submitted the form before today.

What combination of automation tools should LenoxSoft use to achieve this?
A . Automation rule and completion action
B . Dynamic list and automation rule
C . Completion action and dynamic list
D . Segmentation rule and completion action

Answer: A