Answer is combination
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so if you look up things that can cause an asthma attack it will also show that viruses and bacteria are a cause. with asthma you lungs could already be inflamed as well as your air way wich makes it harder to breath. when you have c-19 it will inflame your lungs even more so it makes it even harder to breath given an asthma attack. more asthma attack now are probably caused by c-19 because it is all over the place and the percent of asthma attack by virus has dramatically increased.
It is the last choice because their similar bone structures suggest they once had a common ancestor, which is why they are all mammals.