If its plural (los/las/ more than 1 thing) its gustan
If its singular(la/el/ 1 thing) its gusta
El camino Inca because the sentences says the indigenous cultural route (la ruta indigena cultural) is a road that the ancient indians "los incas" occupy to move from one to one place to another.
1. Harías
2. sabrían
3. pondrías
4. querrían
