A．Advances in iron processing in the eighteenth and nineteenth centuries.
B．The effects of the Industrial Revolution on traditional architectural styles.
C．Advantages of stone and timber over steel as building materials.
D．The evolution of the use of iron in architecture.

A．the impracticality of using iron for small, noncommercial buildings
B．the association of iron architecture with the problems of the Industrial Revolution
C．the general belief that iron offered less resistance to fire and harsh weather than traditional materials
D．the general perception that iron structures were not beautiful in appearance