The formal purpose of such a convention is to select the party's nominee for President, as well as to adopt a statement of party principles and goals known as the platform and adopt the rules for the party's activities, including the presidential nominating process for the next election cycle.
The breeding of livestock played an important role in agricultural development, as did the development of farm tools which were mostly made of stone. Also wheat and rice being planted helped some.
A bill that is vetoed by the president can become law if Congress overrides the veto. In addition, the president may choose to say no by vetoing it. If this occurs, the bill is sent back to Congress. If two-thirds of all the associates of Congress vote yes, the bill can still turn into law. The bill perishes when there are not sufficient votes to supersede the president.
The answer that I have for this question is A