Which one is not a cell of the immune system a)b cells b) t cells c)red blood cells d)white blood cells

All the Cells in the immune system: T-cells, B-cells and NK Cells these are all types of white blood cells. so the answer is C

Stand or kneel behind the child and wrap your arms around his or her waist. locate the navel with one or two fingers in the middle of the child’s abdomen. just above the navel and well below the lower tip of the breastbone