Who was the opponent during the UFC 90 event with a fight that lasted less than 4 rounds?
CREATE TABLE table_52240 (
    "Res." text,
    "Record" text,
    "Opponent" text,
    "Method" text,
    "Event" text,
    "Round" real,
    "Time" text,
    "Location" text
)
SELECT "Opponent" FROM table_52240 WHERE "Round" < '4' AND "Event" = 'ufc 90'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Who was the opponent during the UFC 90 event with a fight that lasted less than 4 rounds? ### Input: CREATE TABLE table_52240 (
    "Res." text,
    "Record" text,
    "Opponent" text,
    "Method" text,
    "Event" text,
    "Round" real,
    "Time" text,
    "Location" text
) ### Response: SELECT "Opponent" FROM table_52240 WHERE "Round" < '4' AND "Event" = 'ufc 90'