Chronic dyspnea ddx part 1

In patients with asthma, which of the following spirometry results is typically observed?

1: An FEV1 to FVC ratio above 0.7
2: A reversible obstructive airflow pattern after administration of inhaled bronchodilators
3: A decreased diffusing capacity of the lung for carbon monoxide (DLCO)
4: An irreversible obstructive airflow pattern after administration of inhaled bronchodilators