Josh manages security at a power plant. the facility is sensitive, and security is very important. he would like to incorporate two-factor authentications with physical security. which of the options below is the best way to meet this requirement?

Question: Josh manages security at a power plant. The facility is sensitive, and security is very important. He would like to incorporate two-factor authentications with physical security. Which of the options below is the best way to meet this requirement?  A) Smart cards B) A mantrap with a smart card at one door and a pin keypad at the other door C) A mantrap with video surveillance D) A fence with smart card gate access   The correct answer is (B) A mantrap with a smart card at one door and a pin keypad at the other door  Explanation: Multi-factor access control systems are access control systems that authorises access only after more than one piece of evidence is presented to authenticate a user. The mechanisms used in multi-factor authentication include 1.  Knowledge (something the user and only the user knows),  2.  Possession (something the user and only the user has), and  3.  Inherence (something the user and only the user is). A two-factor authentication system uses two of these mechanisms to grant or deny access. An authentication system that uses a mantrap with a smart card (possession) on one door and a pin keypad (knowledge ) on the other door is a two factor authentication system.

The answer is b.the gaseous state is electrically positive, while the plasma state is electrically negative. 

Iknow the first part it is the average star i am not 100% sure