Explanation:
The given data is as follows.
Electric field between plates without dielectric, 
Electric field between the plates with dielectric,
.
Permittivity of free space,
= 
Now, we will determine the charge density as follows.

= 
= 
Thus, we can conclude that the charge density on each surface of the dielectric is
.
Answer: 3.26 light years
Explanation:
Each star has a parallax of one arcsecond at a distance of one parsec, which is equivalent to 3.26 light years.
so the parallax of 1 arcsecond will be at a distance of <em>1/1 × 3.26 light years</em>
There is no equation here
This would be B
Hope this helped