4. The challenges of recycling minerals derives from the facts (a) that they may contain more than 40 elements while geological minerals can be made up. (b) do not require a deep understanding of thermodynamics to separate modern products into economically viable metal, alloys, compounds. (c) product designers also have a key role to play in efforts aimed at increasing metal-recycling rates. (d) realizing that it is more resource and cost efficient than throwing the resources away with the waste and starting all over again with mining (3 Points) a.b and c b, c and d a, b and a a cand d all of the above