Moving charged particle 3

The above left diagram shows a particle with electric charge $-1 \text{ C}$ being put at the position $x=0,$ which then moves to the $+x$ direction. The graph on the right shows the electric potential as a function of the particle's position. Which of the following statements is correct?

a) The speed of the charged particle at the position $x=0.4 \text{ m}$ is twice as large as that at the position $x=0.2 \text{ m}.$
b) The electric field strength at the position $x=0.7 \text{ m}$ is twice as large as that at the position $x=0.2 \text{ m}.$
c) The kinetic energy at the position $x=0.8 \text{ m}$ is twice as large as that at the position $x=0.6 \text{ m}.$