The correct answer is B. Many companies organize retreats and other activities so employees can bond with one another.
Explanation
Reciprocal pronouns are used to express a mutual action between two or more people or objects. Those pronouns are "each other" and "one another", the first is to refer to the relationship between two people, while the second is to refer to a situation in which two or more people are involved. According to the above, the correct answer is "B. Many companies organize retreats and other activities so employees can bond with one another" since the reciprocal pronoun is used to refer to the relationship between employees in retreats and other activities.
