Scientists believe that bugs might eat more when temperatures rise primarily because of option c: "Plants become less nutritious because they do not need as many enzymes to fix the carbon in their leaves causing bugs to need to eat more to get the some amount of nutrients."
As temperatures rise and carbon dioxide levels increase, plants may experience changes that affect their nutritional content. This can lead to herbivorous insects needing to consume more plant material to obtain the same level of nutrients, resulting in increased feeding behavior.