Root caries risk in adults is
1. associated with previous enamel caries experience.
2. reduced in communities with fluoridated water.
3. greater in adults who have high streptococcus mutans counts.
4. similar in institutionalized and noninstitutionalized patients.

(2) and (4)

(1) (2) (3)

(1) and (3)

All of the above

(4) only