Option B Binding Of Hb with O2 mainly depends on Partial pressure of oxygen P(O2).. but there are also other factors[ph,temp,P(CO2)] which can interfere.Thats why at high altitude due to less P(O2)binding of haemoglobin decreases so to compensate that body produces more RBC.

Determining the amount of oxygen carried by hemoglobin is a crucial aspect of understanding how oxygen is transported in the body. The correct answer to this question is option 'B' - all options are correct. This means that all of the given factors - pH, partial pressure of carbon dioxide, and partial pressure of oxygen - play a role in determining the oxygen carried by hemoglobin. Let's explore each of these factors in more detail:

1. pH:
- The pH level, or the acidity or alkalinity of a solution, influences the binding of oxygen to hemoglobin.
- Bohr effect describes the relationship between pH and the hemoglobin-oxygen binding affinity.
- When the pH decreases (becomes more acidic), such as in tissues with high carbon dioxide levels, the hemoglobin's oxygen binding affinity decreases.
- This allows for the release of oxygen from hemoglobin to the surrounding tissues.

2. Partial Pressure of Carbon Dioxide:
- The partial pressure of carbon dioxide (PCO2) is another important factor that affects the oxygen binding affinity of hemoglobin.
- An increase in PCO2, such as in tissues with high metabolic activity, leads to a decrease in pH due to the formation of carbonic acid (H2CO3) from the reaction between carbon dioxide and water.
- As mentioned earlier, a decrease in pH causes a reduction in the oxygen binding affinity of hemoglobin, facilitating the release of oxygen to the tissues.

3. Partial Pressure of Oxygen:
- The partial pressure of oxygen (PO2) also plays a role in determining the oxygen carried by hemoglobin.
- In the lungs, where the PO2 is high, oxygen binds to hemoglobin to form oxyhemoglobin.
- In tissues with lower PO2, oxyhemoglobin dissociates, releasing oxygen to be used by the cells.

By considering all of these factors together, we can have a comprehensive understanding of how oxygen is transported by hemoglobin. The balance between pH, PCO2, and PO2 ensures that oxygen is efficiently delivered to the tissues where it is needed.