Which one of the following is a right matching pair of certain organism$(s)$ and the kind of association?

Two closely related species competing for the same resources cannot coexist indefinitely and the competitively inferior will be eliminated eventually. This principle is known as:

$A$ : Fig species and wasp have a tight one-to-one relationship.
$R$ : Angiosperms and insects are coevolved to perform a plant-pollinator interaction.

Niche overlap indicates:

While explaining interspecific interaction of population,$(+)$ sign is assigned for beneficial interaction,$(-)$ sign is assigned for detrimental interaction and $(0)$ for neutral interaction. Which of the following interactions can be assigned $(+)$ for one species and $(-)$ for another species involved in the interaction?

The principle of competitive exclusion was stated by