Answer
The proton can escape out of the region. By conservation of energy, the proton's kinetic energy when it escapes is $2.00~eV$
Work Step by Step
We can find the total energy at $x = 3.5~cm$:
$E = K+U$
$E = K+q~V$
$E = (4.00~eV)+(1e)(3.00~V)$
$E = 7.00~eV$
By conservation of energy, the proton can reach a location where the electric potential is $7.00~V$
Since the electric potential at $x = 6.0~cm$ is only $5.00~V$, the proton can escape out of the region. By conservation of energy, the proton's kinetic energy when it escapes is $2.00~eV$.