Question: What is the primary security concern for the 'application/mbms-protection-description+xml' MIME type, used in MBMS for configuring security functions?
Option 1: Exposure of secret keys within the XML document.
Option 2: Modification of a receiver's understanding of security functions by an attacker (e.g., for denial of service or session replacement attacks).
Option 3: Incompatibility with various MBMS client applications due to encoding issues.
Option 4: Unintended sharing of the XML document itself, which could reveal sensitive network configurations.
Explanation: The correct answer is Option 2 because the primary concern is that an attacker might modify a receiver's understanding of the security functions, leading to denial of service or session replacement attacks. The format itself contains no secret information, mitigating concerns related to exposure of sensitive data (Option 1). Options 3 and 4 are not highlighted as primary security concerns in this context.