Which two types of testing should a technical Architect implement to reduce or eliminate the complaint?

Universal containers is hearing complaints from users that recently released changes while they meet the functional requirements are not actually usable and/or do not meet their expectations for user experience for example, a Visualforce page that takes too long to display the first page of data.

Which two types of testing should a technical Architect implement to reduce or eliminate the complaint? Choose 2 answers
A . user Acceptance Testing
B . Unit Testing
C . Regression Testing
D . Performance testing

Answer: A,D