The answer to the question stated above is letter b. <span> <span>a meteor or asteroid colliding with Earth
</span></span> <span>The mass extinction at the end of the Mesozoic Era was caused by </span>a meteor or asteroid colliding with Earth. This was said to happen about 65 million years ago.
Experimentation (or the experiments the scientist was doing for 10 years) could be wrong or done in an inappropriate way. The only way to know if the information is valid is by checking the way the experimentation (data) was done as well as making sure to check all other factors
b. the first stage because it could never be in the secound stage
