Which aircraft was commonly used in World War 1 starting in 1914?

The Sopwith Camel is often recognized as one of the most iconic fighter aircraft used during World War I, making it a significant choice among the options. Introduced in 1917, the Sopwith Camel was known for its agility and innovative design features, which allowed it to effectively engage in aerial dogfights against enemy aircraft. It played a crucial role in establishing air superiority for Allied forces during the later stages of the war.

The other options listed, while historically significant, did not serve in World War I starting in 1914. The Spitfire, for example, was a crucial aircraft during World War II, specifically known for its role in the Battle of Britain. The British SE5a also emerged later in the war, and while it was a prominent fighter, it did not have its first combat flights until 1917. The P-51 Mustang was developed in the 1940s and is renowned for its performance during World War II. Thus, the Sopwith Camel remains the most fitting choice in the context of aircraft used in World War I starting from 1914.