Inference from sample statistics and margin of error SAT question

Choice B is correct. It's given that $483$ out of $803$ voters responded that they would vote for Angel Cruz. Therefore, the proportion of voters from the poll who responded they would vote for Angel Cruz is $\frac{483}{803}$. It’s also given that there are a total of $6,424$ voters in the election. Therefore, the total number of people who would be expected to vote for Angel Cruz is $6,424(\frac{483}{803})$, or $3,864$. Since $3,864$ of the $6,424$ total voters would be expected to vote for Angel Cruz, it follows that $6,424-3,864$, or $2,560$ voters would be expected not to vote for Angel Cruz. The difference in the number of votes for and against Angel Cruz is $3,864-2,560$, or $1,304$ votes. Therefore, if $6,424$ people vote in the election, Angel Cruz would be expected to win by $1,304$ votes.

Choice A is incorrect. This is the difference in the number of voters from the poll who responded that they would vote for and against Angel Cruz.

Choice C is incorrect. This is the total number of people who would be expected to vote for Angel Cruz.

Choice D is incorrect. This is the difference between the total number of people who vote in the election and the number of voters from the poll.