Fill in the blank with the correct Modal from the options given below:

You _____ take the train rather than the bus as it will save you an hour.

ought to

The correct answer is Option (2) → ought to

Here's why:

* **Might** suggests possibility, but not necessarily recommendation.
* **Ought not to** suggests something is not advisable, which isn't the case here.  
* **Might not** again suggests possibility, but here we want to convey a suggestion or recommendation.
* **Ought to** indicates something is advisable or the right course of action. In this case, taking the train is recommended to save time.
 
So, "ought to" is the most appropriate modal verb to show the suggestion that taking the train is a preferable option.