Simply, apply the formula

and insert the values of m = mass, v = velocity and E = Energy.
The result will be

, m = 1 kg
First choice: the inability of current technology to capture
large amounts of the
Sun's energy
Well, it's true that large amounts of it get away ... our 'efficiency' at capturing it is still rather low. But the amount of free energy we're able to capture is still huge and significant, so this isn't really a major problem.
Second choice: the inability of current technology to store
captured solar
energy
No. We're pretty good at building batteries to store small amounts, or raising water to store large amounts. Storage could be better and cheaper than it is, but we can store huge amounts of captured solar energy right now, so this isn't a major problem either.
Third choice: inconsistencies in the availability of the resource
I think this is it. If we come to depend on solar energy, then we're
expectedly out of luck at night, and we may unexpectedly be out
of luck during long periods of overcast skies.
Fourth choice: lack of
demand for solar energy
If there is a lack of demand, it's purely a result of willful manipulation
of the market by those whose interests are hurt by solar energy.
According to my research I found questions with the same info with option choices and they are:
A.) How many people in the study had the flu?
B.) How many people were included in the study?
C.) What was the average age of the people in the study?
D.) What was the most common occupation of people in the study?
Among those options the answer would be the second choice B)
Looking back at the evolution of humans, we are most closely related to chimpanzees, credited to opposable thumbs