What can cause a gradual loss in tyre inflation pressure?

You answered correctly. Tyre pressure can gradually decrease if the valve cap is missing, as dust or dirt can enter and cause slow leaks. Also, a foreign body such as a nail or shard puncturing the tyre can lead to slow loss of air. Quick and frequent acceleration, however, does not directly affect tyre pressure. When considering gradual loss of tyre pressure, always think about possible leaks or small punctures, not just driving habits. This will help you identify similar questions in the future.