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 ? Select the correct answer using the code given below:

At the present level of technology, drones are highly versatile and widely used for various purposes, including all the activities mentioned: 1. **Spraying pesticides on a crop field:** Correct. Agricultural drones are commonly used for precision spraying of pesticides, fertilizers, and herbicides. They can cover large areas efficiently, target specific spots, and reduce human exposure to chemicals, making farming more precise and sustainable. 2. **Inspecting the craters of active volcanoes:** Correct. Drones are invaluable for environmental monitoring and research in hazardous or inaccessible locations. They can safely fly over active volcanoes to collect data, capture images, and monitor gas emissions, providing critical information for volcanologists without risking human lives. 3. **Collecting breath samples from spouting whales for DNA analysis:** Correct. Specialized drones equipped with collection devices (e.g., petri dishes or nets) are used by marine biologists to collect 'whale snot' (exhalations from whale blowholes). These samples contain cells, bacteria, and DNA, which can be analyzed to assess the whale's health, diet, and genetics, minimizing disturbance to the animals compared to traditional boat-based methods. All three activities can be successfully carried out using current drone technology.