The correct option is D bird and moth
Predation is a type of population interaction, in which one organism called the predator eats another organism called the prey.
In this interaction, the one that gets benefited is the predator and the one that gets harmed is the prey.
Predators maintain the prey population under control. A very good example of this is seen in the case of cactus eating moth and prickly pear cactus. Prickly pear cactus was introduced into Australia in the 1920s. But little was known that it would create havoc by spreading rapidly into millions of hectares of rangeland. Several ways were employed to bring this invasive cactus under control but it was of no great help. Finally, a cactus feeding moth from its natural habitat was introduced into this area. This cactus feeding predator moth successfully brought the rapidly spreading prickly pear cactus under control.
If the predator is too efficient then it can over exploit the prey and thereby the prey species will go extinct. Hence, the prey species have evolved certain defence mechanisms to decrease the impact of predation. For example, the blue jay bird is the predator of the Monarch butterfly. This butterfly during its developmental stage (caterpillar stage) acquires a chemical by feeding on a poisonous weed. Hence, it is highly distasteful to its predator
Hence, option d is correct. The predator of Monarch butterfly and prickly pear cactus respectively are bird and moth.
The starfish Pisaster is a predator of the mussels (molluscs).