Less than or equal to the magnitude of the vector
A=mgh
m=300g=0.3kg
g=9,81 m/s^2
h=10m
A=29.43J
If both particles have the SAME electrical charge, then they repel.
If they have DIFFERENT electrical charge, then they attract.
Protons have + charge .
Electrons have - charge .
So two protons (A) or two electrons (D) push apart.
One proton and one electron (C) pull together.
The answer they are looking for is the last one. However the last two are technically correct but the third one would result in negative work.
Answer: 
Explanation:
In the image attached with this answer are shown the given options from which only one is correct.
The correct expression is:

Because, if we derive velocity
with respect to time
we will have acceleration
, hence:

Where
is the mass with units of kilograms (
) and
with units of meter per square seconds
, having as a result 
The other expressions are incorrect, let’s prove it:
This result has units of
This result has units of
This result has units of
and
is a constant
This result has units of
This result has units of
This result has units of
and
is a constant
This result has units of
and
is a constant
because
is a constant in this derivation respect to
This result has units of
and
is a constant