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 $\mathrm{6,424}$ voters in the election. Therefore, the total number of people who would be expected to vote for Angel Cruz is $\mathrm{6,424}\left(\frac{483}{803}\right)$, or $\mathrm{3,864}$. Since $\mathrm{3,864}$ of the $\mathrm{6,424}$ total voters would be expected to vote for Angel Cruz, it follows that $\mathrm{6,424}-\mathrm{3,864}$, or $\mathrm{2,560}$ voters would be expected not to vote for Angel Cruz. The difference in the number of votes for and against Angel Cruz is $\mathrm{3,864}-\mathrm{2,560}$, or $\mathrm{1,304}$ votes. Therefore, if $\mathrm{6,424}$ people vote in the election, Angel Cruz would be expected to win by $\mathrm{1,304}$ 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.