Answer
See the detailed answer below.
Work Step by Step
$$\color{blue}{\bf [a]}$$
The energy diagram is shown below, note the two horizontal lines.
The 4 block dots are the turning points.
$$\color{blue}{\bf [b]}$$
We know that:
The de Broglie wavelength $\lambda$ gets longer when the particle slows down and loses energy. This means that the distance between the wave nodes of $\psi_{(x)}$ increases where the potential energy $U_{(x)}$ is higher.
The particle is more likely to be found in places where it moves slowly. So, the wave’s height gets bigger in areas where the potential energy $U_{(x)}$ is larger.
