A ceremonial speech is a kind of special occasion speech.
This speech is generally given by an important person in a community to highlight the values and the beliefs of the members of a community. This speech refers to important events for the life and well-being of a community. Therefore, when something important happens, this special occasion calls for a meeting and a ceremonial speech is given.
These options are wrong:
a) introduction: If there is a ceremony, the speaker will not give an introduction to a scientific speech or a story. He / She will make people think about community values.
b) eulogy: this is a speech given when someone has died.