Select the best description of zero-day vulnerabilities. Support your choice by describing why your choice is the best description.
A. Software vulnerabilities, typically in operating systems or web browsers, that enable bad people to steal information from your computer
B. Previously unknown flaw in software that can be used to create a vulnerability
C. Software vulnerabilities that can be exploited before the software vendor can fix it, and before anti-virus or other defensive measures can defend against it
D. Software vulnerabilities that are horded, bought, and sold on the black market, and used to attack computer systems