I believe the correct answer is 40 cm.
Answer:
Positive z direction.
Explanation:
The magnetic force acting on the electron is given by the formula as :

q is the charge on proton
v is the speed of proton
B is the magnetic field
It is mentioned that the proton is moving with a velocity in the positive x-direction. The uniform magnetic field B in the positive y-direction such taht,
q = +e
v = vi
B = Bj

Since, 

So, the magnetic force acting on the proton in positive z axis. Hence, the correct option is (d) "positive z direction".
Answer:
The question is incomplete because the options are not given. We'll solve this question with the options.
There are two properties of negative charges which we have to consider to find the figure of its electrical field.
Firstly, for a negative charge, the electrical field lines are always directed radially outwards and they don't intersect.
Secondly, we know that similar charges repel each other, so there will be no electrical field present directly between these two negative charges. Electrical field line will be present between two charges only when there is a force of attraction.
Taking both of these facts into consideration, the electrical field line between two negatives is represented by the figure below.
Do what?? i know how to do a lot of things to answer but there’s nothing to answer.♀️