Which vehicle has the right of way during merging?

• The vehicle that is already on the highway.
• The vehicle that is merging onto the highway.
• Both have the right of way.
• Neither the merging vehicle nor the vehicles already on the highway have the right of way.
  Explanation:

  "Neither the vehicle merging onto the highway nor the vehicles already on the highway automatically have the right of way. The vehicle merging must yield to the traffic on the highway, and both drivers should adjust their speeds and positions safely to avoid collisions."