6. The A * algorithm does not define what happens when multiple elements on the frontier have the same f-value. Compare the following tie-breaking conventions by first conjecturing which will work better, and then testing it on some examples. Try it on some examples where there are multiple optimal paths to a goal (such as finding a path from one corner of a rectangular grid to the far corner of a grid). Of the paths on the frontier with the same minimum f-value, select one:

(a) uniformly at random

(b) that has been on the frontier the longest

(c) that was most recently added to the frontier.

(d) with the smallest h-value

(e) with the least cost The last two may require other tie-breaking conventions when the cost and h values are equal.