o & ga

In the audio course 3.1 it sais: Kenny: Kuruma de yama *o* nobore masu ka? (engl) Kenny: You can climb [go] up the mountain by car? shouldn't it be : "Kuruma de yama *ga* nobore masu ka" , since there's a ga needet for the "can I" construction? Please tell me if I'm wrong, and where my mistake is.

Hi there, the focus of this sentence is not whether you can climb the mountain but the focus is on whether you can climb it "BY CAR". So in this case, "o" is all right. :D