1. The problem asks for the number of possible choices for each digit in a 4-digit password. 2. Each digit can be any number from 0 to 9 inclusive. 3. This means each digit has 10 possible choices (0, 1, 2, 3, 4, 5, 6, 7, 8, 9). 4. Therefore, the number of choices possible for each digit is $10$.