The correct answer is: encouraged.
To nurture something means to help it grow and develop. In this case, the feeling of brotherhood should be encouraged in the masses. This means that people should be encouraged to feel a sense of connection and belonging to each other. This can be done through various means, such as education, community events, and social media.
The other options are not as appropriate in this context. To bring something means to cause it to happen or exist. To raise something means to lift it up or cause it to grow. To admire something means to think highly of it. While all of these things can be done to encourage a feeling of brotherhood, they are not the most effective ways to do so.
Encouraging a feeling of brotherhood is important because it can lead to a number of positive outcomes. For example, it can promote peace and understanding, reduce conflict, and increase cooperation. It can also make people feel more connected to their community and to each other.