Erotetic Reasoning Test - Puzzle

I was reading on fluid and crystallized intelligence when I stumbled on an interesting kind of puzzle from

http://www.academia.edu/10211127/Deductive_Reasoning_and_Learning_a_Cross-Curricular_Study

(English translation of an exemplary task from Erotetic Reasoning Test)

In the capital of a certain country someone planted a bomb in the palace of the king. The best royal engineer, who arrived immediately, established the following evidence: 1. There are three wires in the bomb: green, red and orange. 2. To disarm the bomb either the green or the red wire must be cut. Cutting the wrong wire will cause an explosion. 3. If the bomb has been planted by Steve, cutting the green wire will disarm it. 4. If the bomb has been planted by John, cutting the red wire will disarm it. Moreover, no one but John would have used the red wire. 5. If the bomb has not been planted on an even day of the month, the culprit is Steve. 6. The bomb has been planted by Steve, or by John, or by someone else. 
Each of the following questions below can be answered either ‘yes’ or ‘no’. Mark the question to which the answer (regardless of it being ‘yes’ or ‘no’) will allow you to establish in the shortest possible time which wire should be cut in order to disarm the bomb: [ ] Was the bomb planted on an even day of the month? [ ] Was the bomb planted by Steve? [ ] Was the bomb planted by John? [ ] Was the bomb planted by someone else than Steve or John?

Justify your choice.

Additional reading:
https://www.academia.edu/11428544/Intelligence_is_Dynamic_and_Can_Be_Taught