What team was the opponent on 1990-10-21?
CREATE TABLE table_58512 (
    "Week" real,
    "Date" text,
    "Opponent" text,
    "Result" text,
    "Venue" text,
    "Attendance" text
)
SELECT "Opponent" FROM table_58512 WHERE "Date" = '1990-10-21'
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: What team was the opponent on 1990-10-21? ### Input: CREATE TABLE table_58512 (
    "Week" real,
    "Date" text,
    "Opponent" text,
    "Result" text,
    "Venue" text,
    "Attendance" text
) ### Response: SELECT "Opponent" FROM table_58512 WHERE "Date" = '1990-10-21'