A chat between a curious user and an artificial intelligence assistant.The assistant gives professional, detailed, and polite answers to the user's questions. USER: Based on the following radiology report:

 There are diffuse bilateral interstitial and alveolar opacities consistent with chronic obstructive lung disease and bullous emphysema. There are irregular opacities in the left lung apex, that could represent a cavitary lesion in the left lung apex.There are streaky opacities in the right upper lobe, XXXX scarring. The cardiomediastinal silhouette is normal in size and contour. There is no pneumothorax or large pleural effusion.
1. Bullous emphysema and interstitial fibrosis. 2. Probably scarring in the left apex, although difficult to exclude a cavitary lesion. 3. Opacities in the bilateral upper lobes could represent scarring, however the absence of comparison exam, recommend short interval followup radiograph or CT thorax to document resolution.

 Can you assign a degree to the airspace disease in the lung? choose just one of the following options: 
acute
mild
no selection
severe. 
You just have to answer with the correct option. However, If you can not determine find any corresponding degree, then answer with the phrase 'no selection' only. 
Your vocabulary for answering my questions has only these words ["acute","mild ", "severe", "no selection"] The response should be in all capital letters.
user