What is the attribute of the business with highest star rating?
highest star rating Max(stars); attribute of business refers to attribute_name
SELECT T3.attribute_name FROM Business AS T1 INNER JOIN Business_Attributes AS T2 ON T1.business_id = T2.business_id INNER JOIN Attributes AS T3 ON T2.attribute_id = T3.attribute_id ORDER BY T1.stars DESC LIMIT 1