The only way of telling about dark energy is our observation of how the universe has been expanding. It basically works the opposite as gravity, pushing things away from it. Thus, the closest answer would be D. The shape of galaxies in cluster galaxies.
Complete question:
A child sits in a wagon with a pile of 0.64-kg rocks. If she can throw each rock with a speed of 7.5 m/s relative to the ground, causing the wagon to move, how many rocks must she throw per minute to maintain a constant average speed against a 3.9-N force of friction
Answer:
The number of rocks per minutes thrown is 49 rocks/min
Explanation:
Given;
mass of the rock, m = 0.64 kg
speed of the rock, v = 7.5 m/s
frictional force,
= 3.9 N
For an object to move at a constant speed, the applied force must be equal to the frictional force.

where;
is the applied force
N/t is the number of rocks per minutes thrown
Substitute the given parameters;

Approximately 49 rocks/min
The answer is D, it increases the susceptibility to infections.
Answer:
part of energy is wasted in heat because of resistance in the filament (and that's how it glows)