The microwave would be your best guess it was first made in 1946
In general, you expect the platform of a political party to "<span>B. Guide the political issues of the party's candidate", since a political "platform" is a group of important issues that resonate with the voters being sought after. </span>
"Each slave was counted as three-fifths of a person" is the way in which the Constitutional Convention resolved the issue of whether or not to count enslaved people when determining states representation in the House, since this seemed to satisfy both the northern and southern states.
Pretty sure its A but i could be wrong