This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Microbiology
Pigment producing atypical mycobacteria - 
Select and explain. 
A. M. fortuitum and M. chelonae, B. M. xenopi and MAC, C. M. gordonae and M. szulgai, D. M. ulcerans
C: M. gordonae and M. szulgai
Answer: C: M. gordonae and M. szulgai 
Explanation: Pigment producing atypical mycobacteria:

Photochromogen: M marinum, M simiae, M. asciaticum, M kansasii,
Scotochromogen: M. scrofulaceum, M szulgai, S.gordonae