Answer
The objects included within the system are the spring, the block, and the Earth.
Work Step by Step
To apply conservation of energy, we would need to consider the elastic potential energy in the spring, the kinetic energy of the block, and the gravitational potential energy of the block-Earth system.
Note that we may also need to consider the geometry of the ramp in order to calculate the change in height of the block, but it is not necessary to include the incline in the system.
The objects included within the system are the spring, the block, and the Earth.
