In the context of solving pollution problems, what is/are the advantage/advantages of bioremediation technique? 1. It is a technique for cleaning up pollution by enhancing the same biodegradation process that occurs in nature. 2. Any contaminant with heavy metals such as cadmium and lead can be readily and completely treated by bioremediation using microorganisms. 3. Genetic engineering can be used to create microorganisms specifically designed for bioremediation. Select the correct answer using the code given below:

Statement 1 is correct: Bioremediation is an environmental clean-up technique that leverages natural biological processes to degrade or detoxify pollutants. It involves using microorganisms (like bacteria and fungi) or plants to break down or immobilize hazardous substances, essentially enhancing natural biodegradation processes already occurring in nature. Statement 2 is incorrect: Bioremediation is highly effective for organic contaminants (e.g., petroleum hydrocarbons, pesticides). However, it is generally *not* effective for heavy metals such as cadmium and lead, because heavy metals are elemental and cannot be 'biodegraded' or broken down by microorganisms in the same way organic compounds can. While microorganisms might sometimes immobilize or transform them into less toxic forms, they cannot 'readily and completely treat' them by biodegradation. Statement 3 is correct: Genetic engineering techniques can be used to modify microorganisms to enhance their bioremediation capabilities. This can involve improving their ability to degrade specific pollutants, increasing their tolerance to toxic environments, or making them more efficient in various conditions. This is a significant area of research and development in bioremediation. Therefore, statements 1 and 3 are correct.