Right option is (d) Iron in aluminum, zinc in brass and 18-8 stainless steel
Best explanation: All the given alloys are prone to intergranular corrosion. Iron in aluminum and zinc in brass are susceptible to this corrosion, due to the segregation of iron and zinc respectively at the grain boundaries. Whereas 18-8 Stainless steel is susceptible due to the depletion of chromium at the grain boundaries.