A. There sre no values assigned to the two sqlnet.ora parameters, CLOUD_ENCRYPTION_SERVER and/ or CLOUD_CRYPTO_CHECKSUM_SERVERor they don't exist on the client.

B. They've specified an RSA key size that's too small to interface with the cloud.

C. The DBA has not enabled native Oracle net encryption in the cloud through the CLOUD_ENCRYPTION_SERVERand CLOUD_CRYPTO_CHECKSUM_SERVERparameters in their cloud instance sqlnet.orafile.

D. They have explicitly set ENCRYPTION_CLIENTand CRYPTO_CHAECKSUM_CLIENTas "rejected" in sqlnet.ora.This will create an unencrypted connection, which will automatically fail because it's insecure.

E. The DBA has set ENCRYPTION_SERVERand CRYPTO_CHECKSUM_SERVERto "required" in the sqlnet.orafile. This will create an unencrypted connection, which will automatically fail because it's insecure.