I think it’s b but I could be wrong
Red Blood Cells i believe are not part of the immune system. They carry oxygenated blood to the organs of the body
Whenever I feel sad, worried, and alone I would just go upstairs with my drawing book and other supplies. I would sit at a corner of the roof gazing the beauty of sky, thhe stars, the clouds, the nature, there I would make anything I found And I will try to find peace in it. This is how feel good after a bad mood.
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If there's something wrong, do lemme know in comments :D
Ask your doctor for advice of course it is reasonable because doctors know how to treat most illnesses