to ag Ricardo wants to arrange three Is, three 2s, two 3s, and one 4 to form nine-digit positive integers with the properties that . when reading from left to right, there is at least one 1 before the first 2, at least one 2 before the first 3, and at least one 3 before the 4, and C . no digit 2 can be next to another 2. (For example, the integer 121 321 234 satisfies these properties.) In total, how many N such nine-digit positive integers can Ricardo make? (A) 278 (B) 260 (C) 254 (D) 272 (E) 266