Which of the following is a common complication of thrombosis due to the obstruction of the artery, reducing the amount of oxygen supply in the body?

Hypoxia is indeed a common complication associated with thrombosis resulting in arterial obstruction. When an artery becomes occluded, it limits blood flow to the tissues supplied by that artery. Since blood is responsible for delivering oxygen to the body's tissues, an obstruction can lead to insufficient oxygen levels, causing hypoxia. This state occurs because the affected areas of the body do not receive an adequate supply of oxygen to meet their metabolic needs.

In various scenarios, particularly in conditions such as deep vein thrombosis or pulmonary embolism, hypoxia can significantly impact organ function and overall health. Therefore, recognizing hypoxia as a direct consequence of arterial obstruction due to thrombosis underscores its importance in the context of vascular health.

The other options, while serious medical conditions, are not direct or common consequences of arterial thrombosis. Respiratory arrest and cardiac arrhythmia can occur in various medical scenarios but are not typically caused specifically by thrombosis in the same direct manner that leads to hypoxia. Hemothorax involves blood accumulating in the pleural cavity, which is unrelated to the mechanisms of thrombosis in arterial obstruction.