Select all that are true of distributed database transparency features. $($Check all that are true.$)$

a$.$

Performance transparency ensures that the system will continue to operate in the event of a node failure.

b$.$

Local mapping transparency exists when the end user or programmer must specify both the fragment names and their locations.

c$.$

Location transparency exists when the end user or programmer must specify the database fragment names but does not need to specify where these fragments are located.