Brian Is a Radio Show Host Who Wants to Prolong

Brian is a radio show host who wants to prolong the Republican primary for president. To do so, he suggests to his listeners (mostly registered Democrats) that they should all go vote in the Republican primary in a closed primary state, to help the second-place candidate win the state and prevent the first-place candidate from getting an insurmountable lead. What is the problem with Brian's plan?

A) According to the rules of the primary in the state in question, registered Democrats cannot vote in the Republican primary.
B) The tactic that Brian is using was deemed illegal in the case Snyder v. Phelps (2011) .
C) Radio listeners are generally less likely to vote than TV watchers.
D) There are likely not enough Democratic voters to overwhelm the Republican voters in the primary.
E) There is no problem; this plan will work perfectly: the Republican primary will continue, and the Democratic Party will have a major advantage at election time due to its extra time to prepare.