Answer:

Explanation:
given,
velocity of particle 1 = 0.741 c to left
velocity of second particle = 0.543 c to right
relative velocity between the particle = ?
for the relative velocity calculation we have formula

u_x = 0.543 c
v_x = - 0.741 c




Relative velocity of the particle is 
U=1/2kx2
This image sums it up
Its resistor :}...............
I think I can answer your question since I've worked on this before.
Your answer should be obtain energy.
If your answer choices were;
obtain energy
escape predators
produce offspring
excrete waste