Question

If they want to succeed, they .............. have to work very hard.

• A. must
• B. ought
• C. should
• D. will

Hint:

For conditional sentences about future necessity, use “will have to” instead of “must” or “should” for stronger accuracy.

Answer 1

The Correct Option is D

This sentence is about a condition for future success — “If they want to succeed” clearly places the action in the future.
When we express a necessity or obligation that applies to the future, we often use the structure “will have to”.
Here, the meaning is: in the future, success will require them to work very hard.
Option (a) “must” is used for expressing strong necessity in the present or near-future, e.g., “You must study tonight.” However, it does not combine naturally with the future condition in this sentence.
Option (b) “ought” expresses moral advice or suggestion, such as “You ought to help the poor.” It does not convey the sense of a firm requirement.
Option (c) “should” indicates recommendation or mild obligation, e.g., “You should eat healthy food.” This is weaker than the certainty implied here.
Option (d) “will” is the most accurate because it matches the predictive and future-oriented meaning of the conditional clause. “They will have to work very hard” means “it will be necessary for them to work very hard in order to succeed.”
Thus, the sentence correctly reads: “If they want to succeed, they will have to work very hard.”
This construction is very common in conditional sentences describing unavoidable future requirements.