In businesses with an owner address 500 California St, 2nd Floor of Silicon Valley, list the type of inspection of the business with the highest score.
the highest score MAX(score); Silicon Valley is located in 'SAN FRANCISCO';
SELECT T1.type FROM inspections AS T1 INNER JOIN businesses AS T2 ON T1.business_id = T2.business_id WHERE T2.owner_address = '500 California St, 2nd Floor' AND T2.owner_city = 'SAN FRANCISCO' ORDER BY T1.score DESC LIMIT 1