Studying an environmental science degree provides you with a broad understanding of current environmental issues and challenges on a local, national and global scale. You learn about the impact humans have on the environment and how to manage it.
The author uses actions as a method of indirect characterization. The writer describes the actions of the character. Hope that helps.
Since an absolute phrase modifies a noun, and is separated from the rest of the sentence using a comma usually, with no conjunctions, the only correct answer here is the first one. Because there is a comma, there is no conjunction like in the third sentence, so it has to be correct.