Which of the following can be used as a biocontrol agent in the treatment of plant disease?

Trichoderma species are free-living fungi that are very common in the root ecosystems. They are effective biocontrol agents of several plant pathogens.Lactobacillus -  used for synthesis of curd.Chlorella- Can be used as food.Anabaena- It is a cyanobacteria which is very useful in fixing atmospheric nitrogen. It can be used to increase soil fertility. Hence, they are used as biofertilizers.