Match the following and choose the correct combination from the options given.
`{:(,"Column I",,,"Column II"),(a., "Potassium",,(i),"Germination of pollen grains"),(b.,"Molybdenum",,(ii),"Involved in synthesis of auxin"), (c., "Boron",,(iii), "Involved in protein synthesis"), (d.,"Zinc",,(iv),"Constituent of ferredoxin"),(e.,"Sulphur",,(v),"Component of nitrate reductase"):}`