Well there are many catastrophic scenarios that we already overcome. You should consider educating yourself about the great filter. A great filter is a hypothetical barrier that each civilization can or cannot overcome. From here on things get a little complex so I won't bore you with them. But there are experts in this theory called great filter and I'm sure they can tell you a lot about.
System failure is one of the more common causes.
B definitely because d is just dumb, c is not possible, a is not even true so b
C. Vegetation
because even though cows are important, all life is and not just that species and then cars and factories are unnatural and would not be critical for the carbon cycle in nature.
Answer:
Transamination reaction:
Transmaination reaction may be defined as a type of chemical reaction that involves the transfer of an amino group to the another keto acid fort the formation of new amino acid. The non essential amino acid can be easily converted to essential amino acid by this transmination reaction.
This reaction is important for the important mteabolic pathways of the body. The cofactor required for the transamination reaction is pyridoxal-5'-phosphate. This cofactor also works as a derivative of vitamin B6. This cofactor is converted to pyridoxamine-5'-phosphate during the reaction.