How did shoe making change during the gilded age?

a. in 1800, shoes were made by hand. in 1900, shoes were being mass-produced in factories.
b. in 1800, shoes were mass-produced in factories. in 1900, shoes were still made in factories.
c. in 1800, shoes were made by hand. in 1900, shoes were still made by hand.
d. in 1800, shoes were mass-produced in factories. in 1900, shoes were made by hand.

In 1800, shoes were made by hand. in 1900, shoes wee being mass-produced in factories.

Explanation:

The Gilden Age was a period that started in the 1870s along with the Industrial Revolution, and as the Industrial revolution brought all this technology and changes in processes of production and social order, they started to make mass production of shoes, they were not made by hand anymore like the unique pieces they used to be.