Please choose the correct ending to complete the given sentence: Health: [header] How to determine positive and negative blood types [title] Understand what determines your rh factor. [step] Located on your red blood cells, the rh factor is a protein you did or did not receive from your parents. You are rh positive when you have the protein.

Ending1: Iron is a hormone that is responsible for aging red blood cells, which can affect your red blood cells faster. [substeps] Instance, your red blood cells are on the present level (rh), which you get from eating a healthy diet, exercising regularly, and using sex right before you get pregnant. Ending2: The extra protein can lower your blood sugar levels and lead to disordered health. You will have rh positive levels in your genes from biochemistry, clinical trials conducted by scientists on the zepeazole group, in donating blood to a dialysis clinic or via donated plasma. Ending3: If the protein is not present, you are rh negative. [substeps] People with positive rh factors have positive blood types, whether a +, b +, ab +, or o +. Ending4: Cellular replication is very similar to your pituitary reproductive ability (pituitary); however, cellular replication by your parents is much more similar to the pituitary reproductive ability, which is where your blood is activated. [substeps] The effect of a certain protein varies depending on the current protein you were tested on.

Answer format: ending1/ending2/ending3/ending4