What purpose I served by including smith’s observations on visiting a pin-making factory ?

500 books can be produced by one man and a printing press within 5 months, while a copyist can only produce one in the same amount of time

he did it to save us from our sins, so we can see him in heaven 1 day. it's because he loves us so much. he used himself as the final sacrifice, so that we could be forgiven for our sins, so that we can see him in heaven, if we believe.

i believe your answer is d)