Exam 1z0-071 topic 1 question 37 discussion

Table can have multiple foreign Key: CREATE TABLE ENCOUNTER ( ENCT_ID VARCHAR2(25) PRIMARY KEY, ENCT_DATE DATE NOT NULL, PT_MRN NUMBER NOT NULL, ENCT_BP VARCHAR2(10) NOT NULL, ENCT_WT NUMBER(3,2) NOT NULL, ENCT_TEMP NUMBER(3) NOT NULL, ACCT_ID VARCHAR2(25) NOT NULL, PHX_ID VARCHAR2(25) NOT NULL, CONSTRAINT FK_PATIENT FOREIGN KEY (PT_MRN) REFERENCES PATIENT(PT_MRN) CONSTRAINT FK_ACCOUNT FOREIGN KEY (ACCT_ID) REFERENCES ACCOUNT(ACCT_ID) CONSTRAINT FK_PTHISTORY FOREIGN KEY (PHX_ID) REFERENCES PTHISTORY(PHX_ID));

CD is correct answer. PFB discussion link for same question https://www.examtopics.com/discussions/oracle/view/21762-exam-1z0-071-topic-2-question-64-discussion/

One pk and yeah if you dont insert anything in a row with a with a varchar datatype the value is null and not an empty string which i guess is what they're trying to trick you into?