Develop the simulation of this module using absorbing boundary conditions. Include a function to show the situation aboveground. Run the simulation employing various initial grids, as follows:

a$.$ As described in the module with various values of probSpore. Describe the results.

b$.$ With exactly one spore in the middle. Verify that the figure seems to agree with Figure $14\mathrm{.}5\mathrm{.}1.$

c$.$ With exactly two spores that are several cells apart toward the middle. Verify that the rings merge into the figure$-$eight pattern observed in nature, as in Figure $14\mathrm{.}5\mathrm{.}2.$

d$.$ With exactly one spore and a barrier. Verify that the results appear to agree with the growth pattern in Figure $14\mathrm{.}5\mathrm{.}3.$