Angina is a condition in which the person feels the pain in the chest which is caused by the reduced blood flow to the heart, therefore, is considered a symptom of coronary artery disease.
The Canadian cardiovascular society has categorised angina on the basis of the symptoms into four types: Class I to IV.
In the given question, the symptoms of angina shown by the person are the strenuous activity on climbing the stairs after meals or climbing are the symptoms of the Class II angina in which the ordinary activities gets severed.