A block of mass M is attached to a spring of negligible mass and can slide on a horizontal surface along the x-direction, as shown above. There is friction present between the block and the surface. The spring exerts no force on the block when the center of the block is located at x=0. At the instant shown above, the block is located at x=0 and moving toward the right with speed v=v0. (a) For the instant shown above, with the block located at x=0 and moving to the right, predict the direction of the net force on the block. If the net force is zero, select “The net force is zero.”

_ To the left _ The net force is zero _ To the right
Briefly justify your prediction.