Bioactive molecule, cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is produced by the fungus -

Trichoderma polysporum

The correct answer is Option (4) → Trichoderma polysporum 

Cyclosporin A is a bioactive molecule that is widely used as an immunosuppressive agent in organ transplant patients. It plays a crucial role in preventing organ rejection by suppressing the immune system's response to the transplanted organ. This important medication is derived from the fungus Trichoderma polysporum.  

Fungi are also known to form symbiotic associations with plants (mycorrhiza). Many members of the genus Glomus form mycorrhiza. The fungal symbiont in these associations absorbs phosphorus from soil and passes it to the plant. 

Statins produced by the yeast Monascus purpureus have been commercialised as blood-cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol.

Streptokinase, produced by the bacterium Streptococcus and genetically modified, serves as a "clot buster" in the removal of blood clots from the vessels of individuals who have experienced a heart attack.