Aerugo, also known as verdigris, is the green "bloom" visible on many

Aerugo, also known as verdigris, is the green "bloom" visible on many copper items, and is produced, like iron rust, over the course of time by the exposure of the metal to the oxygen in the atmosphere.

a) visible on many copper items, and is produced - Correct. ‘Visible’ and ‘is produced’ are related to ‘’green bloom’’ and are parallel.

b) that is visible on many copper items, and which produces – That & Which parallelism error. Also, ‘Produces’ changes the meaning.

c) visible on many copper items, and produces - It seems green ‘’bloom’’ produces sth instead of it is being produced (change in meaning due to passive to active)

d) that is visible on many copper items, and that produces – Same as C

e) which is visible on many copper items, and which is produced – There should be comma before Which. ‘Visible’ and ‘is produced’ are essential information therefore non-restrictive clause with ‘Which’ is wrong.

Correct me if i missed sth....