which two of the following items are valid for ESP cipher algorithms?

When configuring IPSec with IKE, if the transform set includes an ESP cipher algorithm, specify the cipher keys. In a Cisco IOS IPsec transform set, which two of the following items are valid for ESP cipher algorithms?(Choose two)

A.
esp-null, esp-seal

B.
esp-aes 256, esp-aes null

C.
esp-null, esp-aes 512

D.
esp-aes 192, esp-des, esp-3des