What makes a sentence grammatically correct or not?

It's to know your purpose before you read something because a purpose can:

Which line from president reagan’s address sat moscow state university is a fact? a. democracy is the standard by which governments are measured. b. throughout the world, free markets are the model for growth. c. the key is freedom-freedom of thought, freedom of information, freedom of communication. d. every four years the american people choose a new president, and 1988 is one of those years.

For frederick douglass’s address, “what to the slave is the fourth of july? ” (1852)1) does the speaker use fallacious reasoning or logical fallacies? use evidence from the text to support your answers. 2) how effective is the speaker’s response to counterclaims or alternate claims? use evidence from the text to support your answer