CREATE TABLE table_name_77 (competition VARCHAR2, event VARCHAR2, time VARCHAR2)

What Competition has an Event of 4x100 m relay and has the Time of 38.89?
SELECT competition FROM table_name_77 WHERE event = "4x100 m relay" AND time = "38.89"
SELECT "competition" FROM "table_name_77" WHERE "38.89" = "time" AND "4x100 m relay" = "event"