What Is the Purpose of a Steam Integrator Strip That

What is the purpose of a steam integrator strip that is kept with a tray of instruments?

A) To indicate that the items need to be sterilized.
B) To indicate that the items are disposable and do not need to be sterilized.
C) To indicate that the items went through the flash sterilization process.
D) To indicate that the items have been damaged through sterilization.