A hunter is driving a Land Rover, 2.5 m long, due north with a constant speed of 5 m/s along the outskirts of a jungle. At t = 0, the front of the van passes three large anthills. One second later, a monkey drops a coconut from a tree 4 m due north from the anthills. What is the horizontal coordinate of the point from which the coconut was dropped as measured in the reference frame of the van?