A plate with thickness t = in, width b = in is made of an alloy with the fracture toughness K_ic, the yield strength σ_y, and the crack growth behavior shown in the graph to the left.

a) Determine the critical crack length for the given alloy.
b) Calculate the maximum load the plate can withstand before fracture.
c) Discuss the significance of fracture toughness in material design.
d) Evaluate the relationship between yield strength and crack growth behavior.