The answer that you are looking for is A
Beans are a complete protein
If someone believe that is never ethical to eat meat, they believe that right or wrong is defined by personal belief/prejudice
They didn't use god and religion as their right and wrong guidebook, and they also don't use concrete facts as for why is it wrong for human to eat animal unless "because they also have feelings" argument
Biological. I thought that the answer would be evolution but that is not one of the options. I think my answer is right. I hope it is.