What are the lightning flow automation tools?

Answer options:

A.Process Builder
B.Workflow
C.Flow Builder
D.Visual Workflow

Correct Answer: A and C 
Process builder and Flows are the point and click automation tools. Process builder gives you the ability to build processes while the flow builder builds flows. 
Option B is incorrect because the workflow is not considered a lightning flow automation, it can automate certain business processes but it`s not as powerful as process builder and flows. 
Option D is incorrect because the visual workflow was retired and replaced with the flow. 
References: 

https://help.salesforce.com/articleView?id=process_overview.htm&type=5

Correct Answer: A and C 
Process builder and Flows are the point and click automation tools. Process builder gives you the ability to build processes while the flow builder builds flows. 
Option B is incorrect because the workflow is not considered a lightning flow automation, it can automate certain business processes but it`s not as powerful as process builder and flows. 
Option D is incorrect because the visual workflow was retired and replaced with the flow. 
References: 

https://help.salesforce.com/articleView?id=flow_builder.htm&type=5