He is so much preoccupied with his job that he has become indifferent ______ his health.
He is so much preoccupied with his job that he has become indifferent ______ his health.
Explanation
Usually preposition To is used after Indifferent.
Indifferent to health means صحت سے بے خبر
He is indifferent to his health.
I am not indifferent to my health.