Which of the following resonance structures for OCN⁻ will contribute most to the correct structure of OCN⁻?
1) They all contribute equally to the correct structure of OCN⁻.
2) O(1 lone pair)C(2 lone pairs)N(1 lone pair)
3) O(1 lone pair)C-N(3 lone pairs)
4) O(3 lone pairs)–CN(with 1 lone pair)
5) O(2 lone pairs)CN (2 lone pairs)