Exp) Option d is the correct answer.

Hydrogels are water-absorbent, crosslinked polymer networks that can hold large amounts of water. They are used in medical applications, such as wound dressings, drug delivery systems, and tissue engineering. Hydrogels’ biocompatibility, flexibility, and responsiveness to environmental changes make them valuable in biotechnology and soft robotics.

Statement 1 is correct: Hydrogels are widely used in controlled drug delivery systems because they can encapsulate drugs and release them in a controlled manner over time. This application leverages the hydrophilic nature and biocompatibility of hydrogels.

 Statement 2 is correct: Hydrogels can be used in mobile air-conditioning systems. They can absorb and release moisture, which can be useful in humidity control, a crucial aspect of air-conditioning.

 Statement 3 is correct:  Hydrogels can be used in industrial lubricants to improve their properties, such as reducing friction and wear, controlling viscosity, and improving thermal stability.

Source: “https://www.thehindu.com/sci-tech/science/iacs-fabricates-hydrogels-with-tunable-bactericidal-activities/article29362252.ece

https://www.thehindu.com/sci-tech/health/jncasr-scientists-develop-pancreas-mimicking-system-for-responsive-insulin-delivery-in-diabetes-treatment/article67975149.ece”

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6384686/#:~:text=Poly(ethylene%20glycol)%20hydrogels%20are,off%2Dtarget%20sites%20are%20alleviated.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9858193/