Which sentence from the selection best supports the controlling idea that monarchs depend on human help?

a) "Monarchs, being fragile creatures, are reliant on the assistance of caretakers to ensure their survival."
b) "Human intervention plays a crucial role in supporting the delicate existence of monarchs."
c) "Monarchs, with their intricate life cycle, necessitate human aid for their sustained well-being."
d) "The dependence of monarchs on human assistance is evident throughout their life stages."