Final answer:
The number formed by concatenating the positive integers 2024, 2025, 2026, ..., 2124 cannot be determined to be prime without additional information.
Step-by-step explanation:
The number formed by concatenating the positive integers 2024, 2025, 2026, ..., 2124 can be determined to have 404 digits. In order for a number to be prime, it cannot be divisible by any number other than 1 and itself. The fact that the number has 404 digits does not provide any information about its primality. Therefore, the answer to the question is d. Insufficient information.