Question

Fill in the blank with an appropriate modal:
I am sure we _____ succeed.

• A. might
• B. may
• C. would
• D. will

Answer 1

The correct option is D will

• Option D 'will' is the right answer because will is used to talk about the future, to talk about something we believe will happen in the future.
  

The given statement is in future tense so 'will' is the right answer.

• Option A and B are incorrect because 'may' and 'might' express a possibility, but as the speaker says he is sure of success, may and might are not used.
  
• Option C 'would' is incorrect because it is the past tense of will, which is not the tense the speaker is talking in.