The correct answer for the intruder's specialty is option 'C', which is jewel robbery. The intruder does not mention anything about murder or kidnapping, thus eliminating options 'A' and 'B'. However, he explicitly states his specialization in jewel robbery. Let's break it down further to understand the reasoning behind this answer.

Introduction:
The question is asking about the intruder's specialty. We are given four options: murder, kidnapping, jewel robbery, and all of the above. We need to determine which option accurately represents the intruder's claim.

Eliminating Options:
To find the correct answer, we can start by eliminating the options that are clearly not mentioned by the intruder. The intruder does not mention anything about murder or kidnapping, which eliminates options 'A' and 'B'.

Intruder's Claim:
However, the intruder does explicitly state his specialty in jewel robbery. This means that he has expertise in stealing jewels or robbing jewelry stores. Therefore, option 'C' is the correct answer.

Explanation:
The intruder's claim about his specialization is solely focused on jewel robbery. He does not mention any involvement or expertise in murder or kidnapping. Since his claim is limited to jewel robbery, option 'C' is the appropriate choice.

Conclusion:
In conclusion, the intruder's claim about his specialty is jewel robbery. He does not mention murder or kidnapping, eliminating options 'A' and 'B'. Therefore, the correct answer is option 'C'.