Which of the following is used as 'clot buster'?

Streptokinase

The correct answer is Option (1)- Streptokinase 

Streptokinase produced by the bacterium Streptococcus and modified by genetic engineering is used as a‘clot buster’ for removing clots from the blood vessels of patients who have undergone myocardial infarction leading to heart attack.

Cyclosporin A, that is used as an immunosuppressive agent in organ-transplant patients, is produced by the fungus Trichoderma polysporum.

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 .

Antibiotics are chemical substances, which are produced by some microbes and can kill or retard the growth of other (disease-causing) microbes. Penicillin was the first antibiotic to be discovered. Penicillin is produced by the mould Penicillium notatum.