The diagram shows a sphere submerged in water. $P$, $Q$, $R$ and $S$ are forces on the sphere caused by the pressure of the water. Each force acts at right angles to the sphere’s surface. $P$ and $R$ act vertically in opposite directions. $Q$ and $S$ act horizontally in opposite directions. Which statement about the sizes of these forces is correct?
- A$P < R$ and $S = Q$
- B$P > R$ and $S = Q$
- C$P = R$ and $S = Q$ and $P \neq S$
- D$P = R$ and $S = Q$ and $P = S$