What are the ways to conduct penetration testing?

Black Box testing, White Box testing, Grey Box Testing

The correct answer is a) Black Box testing, is testing with the penetrator having no prior knowledge of the system. White Box testing, is testing with the penetrator having near total access in the system. He can have source code, IP addresses etc. This is usually the worst case scenario for a system. Gray Box testing, is a combination of the two tests above. The penetrator has some access of the system, but not complete access.