Consider the following activities: 1. Spraying pesticides on a crop field 2. Inspecting the craters of active volcanoes 3. Collecting breath samples from spouting whales for DNA analysis At the present level of technology, which of the above activities can be successfully carried out by using drones?

Option (D) is correct because modern Unmanned Aerial Vehicles (UAVs) are equipped with specialized sensors and delivery systems that enable precision agriculture, monitoring hazardous volcanic craters, and non-invasive biological sampling like the "SnotBot" used for whales. While some might doubt the feasibility of collecting whale breath (Option 3), this technology is well-established for DNA and health analysis without disturbing the animals. The core concept tested is the multi-sectoral application of drone technology in replacing human presence in dangerous or inaccessible environments.