Step 1: Understanding the Question:
We must pick the correct statements about natural and organic farming.
Step 2: Check A:
Natural farming works as a closed system of farming. This is correct.
Step 3: Check B:
Natural farming does not use artificial inputs supplied by humans. This is correct.
Step 4: Check C:
Traditional farming promoting polyculture is not accepted as a correct statement in the NTA key.
Step 5: Check D:
Organic farming combines scientific knowledge with traditional practices. This is correct.
Step 6: Check E:
Organic farming relies on growing multiple crops on the same space. This is correct.
Step 7: Match with the options:
A, B, D and E are correct, which is option 4.
Final Answer:
The correct statements are A, B, D and E, which is option 4 (as per the NTA final answer key). \[ \boxed{\text{A, B, D and E only}} \]