Which statement about phone model mismatches in Cisco Extension Mobility is true?

Cisco Extension Mobility updates the line CSS$.$

Cisco Extension Mobility always applies the default device profile first.

Cisco Extension Mobility applies either the phone button template of the default device profile or the phone button template of the device profile.

If the phone model of the device profile of the user is different from the actual phone model, Cisco Extension Mobility can only be used when an extra device profile with the correct phone model is associated with the end user.