The gravitational pull of the Sun the interstellar dust attracting heat away from the protosun the process of nuclear fusion the nebular cloud condensing.
Answer:

vector with direction equal to the axis X.
Explanation:
We use the Gauss Law and the superposition law in order to solve this problem.
<u>Superposition Law:</u> the Total Electric field is the sum of the electric field of the first infinite sheet and the Electric field of the second infinite sheet:

<u>Thanks Gauss Law</u> we know that the electric field of a infinite sheet with density of charge σ is:

Then:

This electric field has a direction in the axis perpendicular to the sheets, that means it has the same direction as the axis X.