I think you should go with C or either with D
This is because iron is more reactive than copper in the metal reactivity series.
The late 19th-century United States is probably best known for the vast expansion of its industrial plant and output. At the heart of these huge increases was the mass production of goods by machines. This process was first introduced and perfected by British textile manufacturers.
The right hand side is different because it could have a stronger / weaker cut. idk
Answer:
there were 5 on three of the planes, and four on the fourth
