Final answer:
FTK (Forensic Toolkit) cannot open an encrypted disk without the proper key, as whole disk encryption is intended to secure data from unauthorized access.
Step-by-step explanation:
FTK (Forensic Toolkit) is a software designed for computer forensics analysis. When dealing with whole disk encryption, it is true that FTK, or any other forensic tool, cannot decrypt the contents of the disk without the appropriate encryption key. Whole disk encryption is designed to prevent unauthorized access to the data on the disk, and as such, the encryption key is necessary to unlock and read the contents. If the key is not available, the encrypted data remains inaccessible.