Which is NOT a main duty of the General Assembly?

B is the correct answer because organizing social events such as church picnics does not fall under the main responsibilities of the General Assembly. The General Assembly's primary focus is on governance, addressing theological and constitutional matters, and providing support and guidance to the church as a whole. This includes promoting core values such as charity, truth, and holiness, advising congregations on constitutional issues, and helping to settle disputes that may arise within lower courts. While church picnics can foster community and fellowship among congregants, they are typically managed at the local church level rather than being a concern of the General Assembly.