Ecological equivalents refer as when the different organism occupying similar niches in different geographical areas. For example, grassland ecosystems are dominated by grasses as the produces. But the species of grasses in temperate, semi-arid parts of Australia are largely different from those of a similar climatic are of North America. The mountain goat found at high altitude in mountain areas of North America in an ecological equivalent of Ibex commonly found in the Alps of southern Europe. Hence, option (a) is correct.
Ecotone is a transition area between two biomes. It is where two communities meet and integrate. For example mangroves, forest represents an ecotone between marine and terrestrial ecosystem. Other examples are grasslands, estuary, and riverbank.
Home range- of an animal is the area where it spends its time; it is the region that encompasses all the resources the animal requires to survive and reproduce. Competition for food and other resources influences how animals are distributed in space.
Biotope– A clearly demarcated unit of environment showing the uniformity of principles habitat conditions is known as a biotope. A sand desert, sandy, and rocky beach and marshy land or a unit of the ocean are examples of biotopes.