your answer would be
B complexity
I agree that it is B but would suggest that you also consider the implications of each answer. They are all technically correct.
A is correct simply due to the fact that the longer time passes without an ebola cure, the more people can be potentially infected with it, resulting in less healthy individuals that may be able to volunteer to test potential ebola vaccines. Scientists need healthy volunteers from affected regions in order for rapid clinical trials to occur.
B is correct because of the nature of epidemics. A combination of technical, social, economic, and geographical obstacles slow the progress and dissemination of ebola vaccine information.
C is correct because finance impacts everything from finding resources used in studying ebola to distributing vaccines to affected areas. Economic imbalances or money shortages negatively impact research.
D is correct due to many social factors (more of a subjective answer). Some people think that vaccine distributors discriminate against certain ethnic groups. Others think the governments/other organizations are not effective enough at managing the situation. Still others feel that the search for a cure is not being approached in the right way. In all, there are multiple ways to oppose different aspects of ebola research.
Ultimately, B is correct because it seems to capture the meaning of A, C, and D together.
The way that doctors can best detect medical problems is :
by injecting a radioactive isotope that travels to the target's tissue and measures the amount of radioactive decay.
if the amount is less or mote than normal, he can conclude that the cause of the symptoms is related to that tissue
Complete question:
The exit nozzle in a jet engine receives air at 1200 K, 150 kPa with negligible kinetic energy. The exit pressure is 80 kPa, and the process is reversible and adiabatic. Use constant specific heat at 300 K to find the exit velocity.
Answer:
The exit velocity is 629.41 m/s
Explanation:
Given;
initial temperature, T₁ = 1200K
initial pressure, P₁ = 150 kPa
final pressure, P₂ = 80 kPa
specific heat at 300 K, Cp = 1004 J/kgK
k = 1.4
Calculate final temperature;

k = 1.4

Work done is given as;

inlet velocity is negligible;

Therefore, the exit velocity is 629.41 m/s
<span>Nothing, in terms of the chemistry.
The distance between the electrodes affects the electrical resistance very slightly. Increasing the distance increases the resistance and reduces the current slightly, which reduces slightly the amount of product.
For most practical applications, for electrolysis done in a beaker, varying the distance between the electrodes will make little difference.
Increasing the concentration of the electrolyte will increase the current flow because there are more charged particles to carry charge, and increase the product yield.</span>