Answer:
D. A dairy cow produces milk over several years
Step-by-step explanation:
A dairy cow is reared mainly for milk production and the cattle normally produces lots of milk as long as it’s well fed. This usually goes on for several years and provides income throughout that period and can then be used for beef purpose later on .
The beef cattle is usually slaughtered and the beef used immediately and has no long term use.
This is why dairy cow brings in more income than a beef cow.