Which of the following generalizations is correct?

1. The more elastic the demand and supply of a product, the larger the portion of an excise tax which is borne by buyers.
2. The more inelastic the supply of a product, the larger the portion of an excise tax which is borne by buyers.
3. The more elastic the demand for a product, the larger the portion of an excise tax which is borne by buyers.
4. The more elastic the supply of a product, the larger the portion of an excise tax which is borne by buyers.
5. The more inelastic the demand for a product, the larger the portion of an excise tax which is borne by sellers.