Which condition in a nebula would prevent nuclear fusion?

A.

the presence of nitrogen and carbon

B.

the unification of gaseous elements

C.

a decrease in the overall volume of gases

D.

a core temperature of only ten thousand Kelvin

E.

physical contact between bare nuclei

Answer: Option D

Explanation:

The nuclear fission in the nebula takes place when the temperature reaches 15,000,000 degrees Celsius. It takes place in the core, center of the cloud.

The other conditions are: presence of gases like nitrogen and carbon, unification of elements and physical contacts between the bare nuclei.

The tremendous heat given off by the nuclear fusion aids in glow creating the pro star. This is the first step of evolution of star.

Hence, the conclusion is that a core temperature of ten thousand Kelvin is equal to 9726.85 Celsius (°C) which is not optimum for the nuclear fission.

So, the correct answer is option D