Option D is the most accurate answer because CHFI v11 explicitly includes Android and iOS forensic analysis , logical and physical acquisition of Android and iOS devices , Android and iOS file systems , and APFS file system analysis as major mobile-forensics objectives. Android devices are commonly associated in forensic contexts with Ext4-based storage structures , while iOS devices use APFS , which introduces additional complexity due to Apple's security model, sandboxing, and strong encryption protections. That makes iOS extraction and examination more dependent on specialized methods and tools. This matches the CHFI view that mobile platforms require different forensic strategies rather than one uniform method. Option A reverses the practical situation. B is incorrect because FAT32 is not the shared native forensic file- system answer for both platforms. C contains a partially plausible idea about iOS complexity, but it is less precise and less aligned to the file-system-focused wording than D . Therefore, based on CHFI mobile- forensics objectives, the strongest answer is that Android commonly uses Ext4 , while iOS uses APFS and often requires more specialized forensic handling.