What Chassis ranked 18th?
CREATE TABLE table_71127 (
    "Year" real,
    "Entrant" text,
    "Class" text,
    "Chassis" text,
    "Engine" text,
    "Tyres" text,
    "Rank" text,
    "Points" real
)
SELECT "Chassis" FROM table_71127 WHERE "Rank" = '18th'
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 Chassis ranked 18th? ### Input: CREATE TABLE table_71127 (
    "Year" real,
    "Entrant" text,
    "Class" text,
    "Chassis" text,
    "Engine" text,
    "Tyres" text,
    "Rank" text,
    "Points" real
) ### Response: SELECT "Chassis" FROM table_71127 WHERE "Rank" = '18th'