CREATE TABLE table_40168 ("Week" CLOB, "Date" CLOB, "Opponent" CLOB, "Result" CLOB, "Game site" CLOB, "Record" CLOB, "Attendance" FLOAT)

Who did the Texan's play on Week 4?
SELECT "Opponent" FROM table_40168 WHERE "Week" = '4'
SELECT "Opponent" FROM "table_40168" WHERE "Week" = '4'