Which of the following should you use to achieve this?

You are employed as a developer at ABC.com. ABC.com has a single Active Directory domain,
named ABC.com.
You are creating a new workflow custom activity via Microsoft Visual Studio 2012, which will be
used in custom action in SharePoint.
You have to start by creating a new custom action.
Which of the following should you use to achieve this?

A.
Display templates.

B.
Design Manager.