To find the number of all numbers that can be formed using some or all of the digits 1, 3, 5, 7, and 9 without repetitions, we can use the concept of permutations.

Permutations are arrangements of objects in a specific order. In this case, the objects are the digits 1, 3, 5, 7, and 9. Since we are not allowed to repeat any of the digits, we need to consider all possible arrangements without repetition.

Let's analyze the problem step by step:

1. Determine the number of choices for the first digit:
- Since we can use some or all of the digits, we have 5 choices for the first digit.

2. Determine the number of choices for the second digit:
- After choosing the first digit, we have 4 remaining digits to choose from.
- Therefore, we have 4 choices for the second digit.

3. Determine the number of choices for the third digit:
- After choosing the first two digits, we have 3 remaining digits to choose from.
- Therefore, we have 3 choices for the third digit.

4. Determine the number of choices for the fourth digit:
- After choosing the first three digits, we have 2 remaining digits to choose from.
- Therefore, we have 2 choices for the fourth digit.

5. Determine the number of choices for the fifth digit:
- After choosing the first four digits, we have 1 remaining digit to choose from.
- Therefore, we have 1 choice for the fifth digit.

Now, we can find the total number of possible arrangements by multiplying the number of choices for each digit:

Total number of arrangements = 5 * 4 * 3 * 2 * 1 = 120

Therefore, the correct answer is option A) 325.