The word essential in paragraph 4 is closest in meaning to .

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word for each of the questions from 44 to 50.
The preservation of natural resources is a critical challenge that requires innovative solutions and technological advancements. As the global population grows and the demand for resources accelerates, the need for smarter, more efficient methods of conservation becomes paramount. Innovation in this field is not just about creating new technologies but also about rethinking our approach to resource management.
Technological advancements have the potential to revolutionize the way we use and conserve natural resources. For instance, advancements in renewable energy technologies, such as solar and wind power, are reducing our reliance on fossil fuels and helping to decrease greenhouse gas emissions. Similarly, precision agriculture uses data and technology to optimize crop yields and reduce waste, thereby conserving water and soil quality.
Innovation also plays a role in monitoring and protecting ecosystems. Cutting-edge tools like satellite imagery and drones provide valuable data on deforestation, wildlife populations, and environmental changes. This information is crucial for making informed decisions about conservation efforts and for tracking the effectiveness of those efforts over time.
Water resources, essential for all life, are under increasing stress due to pollution and overuse. Innovative water purification and desalination technologies are expanding access to clean water, while smart irrigation systems ensure that crops receive the right amount of water at the right time, minimizing waste. The role of technology in resource conservation is not limited to large-scale projects. On a smaller scale, apps and devices that monitor energy and water usage can empower individuals to make more sustainable choices in their daily lives. These user-friendly tools make it easier for people to understand their impact on the environment and that they should take steps to reduce it.
(Adapted from https://alewk.com/blog/sustainable-technology-innovations)