Answer:
The most reliable source is nationalnaturalreserves.gov
Step-by-step explanation:
Websites on the internet has various domains depending majorly on the services offered by the website. Example; websites that are meant for the provision of commercial services have the .com extension in their domain name, so as to give a little information about the type of services that can be found on the website. Furthermore, most academic websites has .edu. extension as part their domain name to make it obvious that it is majorly for an educational purpose.
So, Juan should consider nationalnaturalreserves.gov as a reliable source of scientific information because the .gov extension indicates that the website is a government website which would have a lot of reliable information.