Step 1: Understanding the conditional sentence.
This is a first conditional sentence. Structure: If + Present tense, will + base verb.
Step 2: Analyze the options.
(A) would: Incorrect — “would” is used in second conditional (If + past tense).
(B) will: Correct — “If you work hard, you will pass.” This follows the first conditional structure.
(C) could: Incorrect — “could” expresses possibility, not certainty.
(D) might: Incorrect — “might” expresses weaker possibility, not definite result.
Step 3: Conclusion.
Thus, the correct answer is (B) will.