Which situation is most likely to cause an increase in inter specific competition

one thing that could cause inter species competition is territory and lack of resources.

Answer: Scarcity of food

Explanation:

When two or more organisms, though of different species (e. g lion and tiger), feed on the same kind of prey, then there might be interspecific competition as there would be scarcity or limited food resources to feed on in the area

For instance:

Lion and tiger competes for the flesh of zebras. There is interspecific competition once zebras become scarce