Question

if receiver autonomous integrity monitoring (raim) capability is lost in-flight,
gps position is reliable provided at least 3 gps satellites are available.
the pilot has no assurance of the accuracy of the gps position.
the pilot may still rely on gps derived altitude for vertical information.

Explanation:

RAIM is designed to detect GPS position errors and ensure integrity. When RAIM is lost, there is no built-in check to confirm the accuracy of the GPS position. 3 satellites can give a position but no integrity check, and GPS-derived altitude is not reliable without RAIM either.

Answer:

The pilot has no assurance of the accuracy of the GPS position.