How should the administrator complete this requirement?

The administrator at universal containers has a screen flow that helps users create new leads.

When lead source is “Search Engine”, the administrator needs to require the user to choose a specific a search engine from a picklist. If lead source is not “Search Engine”, this picklist should be hidden.

How should the administrator complete this requirement?
A . Assign a decision element to direct the user to a second screen to hold specific search engine only when a lead source is “Search Engine”.
B . Use an assignment element, one for when lead source is “Search Engine” and one for everything else.
C . Create a picklist for specific search engine, and set conditional visibility so that is only shown when lead source is “Search Engine”.
D . Configure a picklist for specific search engine, and use a validation rule to conditionally show only when lead source is “Search Engine”

Answer: C