Which of these best describes machu picchu, shown here?

a) it contains the tallest religious statue in the world (32 meters high), located in rio de janeiro, brazil
b) it is an ancient incan citadel made of dry-stone walls (instead of mortar), located in the andes mountains of peru.
c) it is an ancient mayan citadel containing the tallest pre-columbian structure in the americas, located in guatemala.
d) it is a monument that was named after a nearby small island and forms a natural barrier between paraguay and brazil.