I’d advise ----- your tickets well in advance if you want to

I’d advise _____ your tickets well in advance if you want to travel in August.
A.to buy B.buy C.buying D.to sell
You can hardly imagine a child ____________ so cruelly.
A.to treat B.being treated C.treats D.treating
I’m too tired and don’t feel like ______ today.
A.study B.studying C.studied D.to study