I can't even think _____ travelling ______ public bus.

I can't even think _ travelling __ public bus.

Off, to

Of, by

Of, On

From, Towards

Think of means کسی منصوبہ بندی کیلئے سوچنا

We generally use preposition By before transports like by bus, by car, by air etc.

I can't even think of travelling by public bus.