cryptography/security engineering

Which one of the following statements is correct regarding basic security services in cryptography? Select one: a. A reliable "freshness" mechanism is necessary to achieve data origin authentication. b. It is possible to achieve non-repudiation with symmetric key cryptography by involvement of a trusted third party. c. Non-repudiation relies on a reliable "freshness" mechanism. d. It is impossible that a cryptographic algorithm provides entity authentication without providing data integrity, and vice versa. e. Acryptographic primitive that provides non-repudiation also provides confidentiality