The M. pneumoniae, which can cause walking pneumonia, is resistant to penicillin due to the absence of a cell wall. Which of the following is, therefore, true?

• A. The strain acquired resistance due to misuse of penicillin.
• B. The strain developed resistance over time upon exposure to penicillin.
• C. The strain has intrinsic resistance to penicillin.
• D. The strain has mutated acquiring resistance to penicillin.

Answer: (C)