Which answer is a correctly punctuated compound sentence?

A.
Technology changes quickly and what is up-to-date today is old-fashioned next month.

B.
Technology changes quickly what is up-to-date today is old-fashioned next month.

C.
Technology changes quickly, what is up-to-date today is old-fashioned next month.

D.
Technology changes quickly; what is up-to-date today is old-fashioned next month.