A commemorative speech is one where a person gives a speech praising the other person who, at times, has already died by having a profound influence and impact on others. And the main theme of this speech is to emphasize the 'values' laid or depicted by the person praised or talked about.
In giving a speech where he praised Martin Luther King and his leadership during the civil rights movement, Barack Obama brings attention to the work of King and his values, the values he laid down throughout his life. This is what constitutes a commemorative speech.
"Keep", "factor", and "calculate" are all verbs in the list of things the new system allows teachers to do. The other sentences are inconsistent with their list of verbs/adjectives/nouns. Thus, option A is the only one that is grammatically correct.
Can you provide the passages? I can help you compare! It's quite easy to compare, make sure you summarize both and say how they are the same. Make sure to also talk about how they are different.
