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 $$x=0.6 \text{ m}.$$

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