You must study () pass the test.

• A. In Order To
• B. In Order That
• C. So That
• D. For To

Answer: (A)

Expressing purpose with an infinitive phrase is the idea here. When you want to say why you do something, you use “in order to” followed by the base verb. You must study in order to pass the test expresses a clear purpose: the study is done so you can achieve passing the test, and the sentence remains natural and direct.

Other patterns are less fitting in this exact line. “In order that” would need a full clause after it (for example, “in order that you may pass the test”), which makes the sentence more formal and wordier. “So that” also requires a clause with a subject and a verb (for example, “so that you can pass the test”). “For to” isn’t a standard way to link purpose in English.