Read the following article and answer the question. Article: I spend a lot of time backpacking and hiking the outdoors and there are two pieces of equipment that are with me on each trip: an Adventure Medical Kits Weekender and an Adventure Medical Kits Suture Syringe Kit. Both proved very helpful on my most recent adventures to the Wrangell in Alaska. On that day, we were "blessed" with rain, making our water crossing on the Dixie Pass very difficult. Our party of 12 had almost reached our destination when I slipped, severely gashing my knee open in the process. While I could not see the wound at first because of the rain pants I was wearing, I knew _ was severe. Blood was running freely and I made those standing nearby aware of the damage. They quickly came over to assist, pulled my pack off and removed the Weekender First Aid Kit and Suture Kit from it. Fortunately, one of my partners is a doctor called William, who has often performed this type of work in the operating room, not out in the wild. I seriously think he was more nervous about all this than me! I, of course, was more than happy that I did not have to stitch myself up. As a marine, I've had to do it before. Fortunately, the sky had cleared up about two hours before, so we had great sunlight to work with. The doctor worked quickly with the assistance of another fellow camper acting as a nurse and placed seven stitches into my knee once the wound had been cleaned up. Later that evening we used a syringe we set aside loaded with Iodine to clean the wound and then bandaged it again. The doctor was very impressed with the kits contents! I've already ordered another Suture Syringe Kit. I have to say the kits are worth their weight in gold! Thanks for the contents in the kits! Question: From the passage, we can infer that the kits are _ . Answer:
Choose from: a). useless b). extremely useful c). troublesome d). not essential
b).