A country has raised the export tariffs of fertilizer products four times to curb the export of fertilizer products. However, the country's export of fertilizer products is still increasing and it still has strong competitiveness in the international market. Which of the following cannot explain this situation:. ['Fertilizer products are in short supply in the international market.', "The quality of the country's fertilizer products has a good reputation in the international market.", 'Prices of fertilizer products in the country remain lower than in other countries after tariff increases.', 'Production of fertilizer products in the country is still increasing.']