If the GDP growth rate is greater than 3%, the per capita income of urban residents and farmers must increase. Assuming the above inference is correct, which of the following must be correct? ['The per capita income of urban residents and farmers has increased, so the GDP growth rate must be greater than 3%.', 'The per capita income of urban residents has increased, while the per capita income of farmers has decreased, then the GDP growth rate must be less than or equal to 3%.', 'If GDP growth rate is less than or equal to 3%, the per capita income of urban residents must decrease.', 'Even if the per capita income of urban residents and rural areas has decreased, the GDP growth rate may be greater than 3%.']