In complete denture construction, a custom tray should be fabricated to ensure that
1. the flanges are not overextended.
2. the distal extension is adequate.
3. there is relief for muscle attachments.
4. the tray has adequate space for the impression material.

All of the above.

(1) (2) (3)

(1) and (3)

(2) and (4)

(4) only