Noel Knows That Which Among the Following Statements Is True

Multiple Choice

Noel knows that which among the following statements is true regarding biosafety cabinets.

A) There are four classes of biosafety cabinets used in the laboratories.
B) Both Class I and Class II biosafety cabinets are able to serve as primary barriers that protects both the lab workers and the environment.
C) Class II biosafety cabinets are not able to provide protection from external contamination of materials.
D) Class IV biosafety cabinets provide the greatest level of protection for both the lab personnel and the environment.