Five equal-mass particles (a-e enter a region of uniform magnetic field directed into the page. they follow the trajectories illustrated in (figure 1. part a which particle (if any is neutral?

We have particle A which is curved to the left-hand side.

Particles B is slowly bent to the right side.

Particle C curves towards the right side.

Particle D is perpendicularly straight.

The particle E bends towards the right side.

Therefore D is showing none deflection then it is the part D which is neutral