Choose the best option to fill in the blank with the appropriate Preposition :

It was now too late to think _______ returning to my home.

of

The best option to fill in the blank is "of".

The complete sentence is:

It was now too late to think of returning to my home.

The preposition "of" indicates a thought or consideration. It implies that the person is pondering the possibility of returning home but realizes that it is too late to do so.