"the other words or phrases that surround it"
The other three options more describe what the word means, or how it is defined. Context is more how a word is used in a text. For instance, the word "cow" can be used as (obviously) a common animal, or can be used as insult against a person. Looking at the word "cow" by itself, you might think it is about the animal. However, if the text is "That woman is an awful cow!" then you can use the words surrounding it to find the context. Hope that makes sense.
