Which of the following block ciphers XORs each block of plaintext with the previous block of ciphertext before being encrypted?

Which of the following is used to uniquely identify records in a table?

(A) a Rule of Referential Integrity (B) a foreign key (C) a primary key (D) a relational database

Which of the following statements creates a multidimensional array with 3 rows, where the first row contains 1 element, the second row contains 4 elements and the final row contains 2 elements?

a. int[][] items = {{1, null, null, null}, {2, 3, 4, 5}, {6, 7, null, null}}; b. int[][] items = {{1}, {2, 3, 4, 5}, {6, 7}}; c. int[][] items = {{1}, {2, 3, 4, 5}, {6, 7}, {}); d. int[][] items = {{1}, {4}, {2}};