From the sentence we can conclude that the goal is to reach John's house and the subject needs directions. Thus, the verb must have a meaning close to 'reach'.
Option A is incorrect. Ride indicates that the subject is inquiring about the means of reaching John's house and not 'how to reach'. Thus, it is not the best fit.
Option B is correct. In this context get means 'Reach a destination by movement'. Thus, it is the closest in meaning to 'reach'. Therefore, it is the best fit.
Option C is incorrect. Shut means 'close'. Thus, it does not fit in the blank at all.
Option D is incorrect. Open is also not close in meaning to 'reach' and thus it is the incorrect option.