Answer:
you are using your shoulder muscle. The reason you are using this muscle is when you put your arm strait up there is no reason to use a bicep or tricep muscle.
Explanation:
The correct answer is letter A. Venom glands and varied diets are the reasons why cane toads are considered as invasive species in Australia. They cause major ecological imbalance within their immediate surroundings and have caused an infestation all over Australia.
I believe it's B. That would be the best guess
Sugar is needed for scientists to grow plants