What can help alleviate discomfort caused by a sinus block?

All of the listed options can contribute to alleviating discomfort from a sinus block, but yawning deliberately specifically is particularly effective because it helps equalize pressure in the sinuses and Eustachian tubes. This action induces a reflex that improves airflow and can relieve the sensations associated with pressure buildup.

Drinking fizzy drinks and chewing gum can also assist in relieving sinus discomfort. Carbonated beverages can promote burping, which may help release pressure, while chewing gum encourages swallowing, which can facilitate opening the Eustachian tubes.

Therefore, combining these actions provides a comprehensive method for reducing the discomfort arising from sinus block, making the correct response inclusive of all the options provided.