Why Is the Razor-And-Razor-Blade Model Also Known as the Printer-And-Ink

Multiple Choice

Why is the razor-and-razor-blade model also known as the printer-and-ink model?

A) the technique is only used by printing companies
B) the razor blade is not used that much
C) the printer is sold at a low cost, but ink or toner is priced much higher
D) printers are expensive, but ink is readily available