Which one of the following population interactions is widely used...

Amensalism is any relationship between organisms of different species in which one organism is inhibited or destroyed while the other organism remains unaffected. It is a type of ecological interaction. A very prominent example of ammensalism is observed during the production of antibiotics. The production of penicillin by Penicillium on a nutrient agar medium shows a zone of inhibition in which other microbes cannot grow. This interaction is also called antibiosis, in which Penicillium gains nothing but adversely affects other microbes.