In general, you expect the platform of a political party to.

ALead to a national convention.
BGuide the political issues of the party's candidate.
CConsist of party leaders called planks.
DDetermine the outcome of a general election.

Verified Answer :

In general, you expect the platform of a political party to "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.