Read the passage. People have been using the milk that cows produce for hundreds of years. For generations, people milked cows by hand. Generally, they could milk six cows per hour. However, once machines came along, they changed the dairy industry. Some people think milking by machine seems mean or cold. But today’s milking process is superior.

During the revision process, the writer will most likely improve the argument by adding which sentence at the end?

Refrigeration started in 1880, making milk more available.
Today's farm machines can milk more than 100 cows an hour.
The majority of farms today are still owned and run by families.
"We've had a dairy cow for years," local farmer Pat Cooper said.