Which of the following statements is correct?

Which two of the following changes $((i)$ to $(iv))$ usually occur in plain dwellers when they move to high altitudes ($3500 \ m$ or more)?
$(i)$ Increase in red blood cell size
$(ii)$ Increase in red blood cell production
$(iii)$ Increased breathing rate
$(iv)$ Increase in thrombocyte count

The respiration rate is lowest while

Which one of the following statements is incorrect?

What does abdominal breathing indicate?

What are the functions of hemoglobin and chlorophyll?