The nurse walks into the room of a client who has had surgery for testicular cancer. The client says that he’ll be undesirable to his wife, and he becomes tearful. He expresses that he’s spoiled a happy, satisfying sex life with his wife, and says that he thinks it might be best if he would just die. Based on these signs and symptoms, which nursing diagnosis would be most appropriate for planning purposes ？（）
A．Situational low self-esteem.
B．Unilateral neglect.
C．Social isolation.
D．Risk for loneliness.