If I had studied harder at college, I ______ to a better university.

- উল্লেখিত প্রশ্নের সঠিক উত্তর হচ্ছে could have gone.

 • 3rd Conditional এর নিয়মানুযায়ী,
- If + Past Perfect (had +V3) + Perfect Modal (Sub + would have/could have/might have + V3).
Example of Sentences:
If I had studied harder at college, I could have gone to a better university.
If we had never met, my life would have been a lot less complicated.
If hadn't taken the job, I might have regretted it.

Source: Cambridge Dictionary.