Final answer:
Lula's antagonism towards Jem and Scout is due to a perceived threat to the black community's space, while Cal responds protectively, upholding equality and respect.
Step-by-step explanation:
The antagonism of Lula towards Jem and Scout in To Kill a Mockingbird can be explained by her perception that the integration of white children (Jem and Scout) into a black church disrupts the sanctity and safety of their space. Lula feels that the white children's presence challenges the black community's autonomy. Calpurnia, or Cal, responds to Lula's antagonism by firmly defending Jem and Scout's right to be at the church, demonstrating her protective and authoritative nature, as well as her belief in equality and the importance of kindness and respect towards all.