A catchment may be idealized as a rectangle There are three rain gauges located inside the catchment at arbitrary locations. The average precipitation over the catchment is estimated by two methods: (i) Arithmetic mean (PA) and (ii) Thiessen polygon (PT).Which of the following statements is correct?

• A. PA is always equal to PT
• B. There is no definite relationship between PA and PT
• C. PA is always greater than PT
• D. PA is always smaller than PT