Two prides of lions compete with one another for the same prey antelope, which scenario would cause a decrease in competition

Wildfire kills many antelope, and some lions
And invasive species outcompete and replaces antelope
A disease kills individuals from the lion population
Drought reduces the water available for all species

The scenario that would cause a decrease in competition between the two prides of lions is if a disease kills individuals from the lion population. This would decrease the number of lions competing for the same prey antelope, leading to less competition.