An air pressure contour line joins locations in a region having the same atmospheric pressure .The following is an air contour plot of a geographical region . Contour lines are shown at 0.05 bar intervals in this plot.

If the possibility of a thunderstorm is given by how fast air pressure rises or drops over a region, which of the following regions is most likely to have a thunderstorm?
(A) P
(B) Q
(C) R
(D) S