What action allows a snowmobile to accelerate?

Pushing the throttle lever is the action that allows a snowmobile to accelerate. When the throttle lever is pressed, it increases the flow of fuel and air to the engine, resulting in more power output. This increase in power causes the snowmobile to gain speed as the engine works more efficiently. Proper use of the throttle is essential for controlling acceleration and ensuring a smooth ride, as it directly affects the vehicle's responsiveness and performance on the snow.

The other options involve actions that either slow down the vehicle or affect its steering rather than increase speed. Pulling the brake would decelerate the snowmobile, while turning the handlebars sharply is related to steering rather than accelerating. Depressing the foot pedal may not be a common action associated with accelerating on most snowmobiles, which typically utilize a throttle lever for that purpose.