What factor is crucial when managing a motorcycle wobble?

Answer: B — Gradually closing the throttle

Gradually closing the throttle is crucial when managing a motorcycle wobble because it helps to stabilize the bike. When a wobble occurs, it often indicates that the motorcycle's balance is disturbed, which can happen due to excessive speed or abrupt maneuvers. By gently reducing throttle, the rider allows the motorcycle to reduce speed in a controlled manner, which can help to restore stability. This gradual reduction prevents sudden shifts in weight distribution that could exacerbate the wobble. In contrast, checking the mirrors, while important for overall safety and awareness, does not directly impact the immediate stability of the motorcycle during a wobble. Increasing speed can further aggravate a wobble situation, as the momentum can intensify the oscillation. Changing gears might not be helpful in addressing the underlying issue of stability during a wobble. Therefore, the best response to manage a wobble is to gradually close the throttle to regain control and stability.