Read the passage below. which term best describes how the phrase "in addition" is used in the passage?

passage: "humans first began planting crops during the neolithic revolution. in addition, they also began domesticating animals."

a. it acts as a conclusion to summarize the passage's claim.
b. it acts as a transition to connect the two sentences.
c. it acts as a marker to demonstrate that the passage is biased.
d. it acts as a citation to prove that the statements are true.