Which statement illustrates an external locus of control?

$"$If I study hard, I have a better chance of getting a high score on the test."

"Even though this is a tough subject for me$,$ I can improve my score on the test

by studying."

$"$If I do poorly on the test, I will have to study harder the next time."

$"$No matter how hard I study, the test will be too hard."