Which number representation takes the largest amount of memory?

Question

Options are:

1. Signed magnitude
2. One's complement
3. Two's complement
4. Excess notation

This is the question from an 'example of a previous exam' I've been given at university. Answers were not provided. As far as I understand only one answer must be chosen, but I'm not seeing which one.

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My attempt at solution

As we see from Signed number representations wikipedia article, both 1. Signed magnitude and 2. One's complement can be chosen as representations requiring the largest amount of memory, because they take up space for both negative and positive 0 (unlike 3. Two's complement and 4. Excess notation).

Is this reasonable, can we say that both 1. and 2. should be chosen as an answers here despite question requiring only one answer?