Universal Container’s Salesforce Admin has enabled knowledge in lightning for his company org. What will happen because of enabling the knowledge in lightning? (Choose two options)

Answer options:

A.Once enabled in lightning, knowledge cannot be disabled
B.Once enabled in lightning, knowledge will appear in the object manager
C.Once enabled in lightning, all classic knowledge articles will be automatically deleted
D.Once enabled in lightning, knowledge can be disabled

Correct Answer: A and B 
Option C is incorrect because once knowledge articles are enabled in lightning, classic knowledge articles will not be automatically deleted because part of enabling knowledge articles in lightning is migrating all the articles from classic to lightning. 
Option D is incorrect because once enabled in lightning, knowledge cannot be disabled. 
Reference:

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