What inappropriate action did the individual take regarding pets on a flight?

Transporting a dog without proper restraint is the correct action that reflects an inappropriate behavior regarding pets on a flight. Airlines have strict regulations aimed at ensuring safety and comfort for all passengers, including those traveling with pets. Not properly restraining a dog can lead to a multitude of dangers, such as the pet obstructing aisles, causing distractions to crew members, or posing risks to the safety of other passengers and animals. This action not only violates airline policies but also demonstrates a lack of consideration for the well-being of the pet and the people on board, highlighting the importance of following safety protocols when it comes to animal transport during flights.

The other actions listed either suggest over-caution or adherence to safety protocols rather than missteps, making them inappropriate choices for identifying a wrong action concerning pets on a flight.