Identify the comma rule that the following sentence breaks:
In their homeroom classes, students learned of a new very strict rule that would affect their parking privileges.
A) Use a comma to separate three or more items in a series.
B) Use a comma to set off a phrase or clause at the beginning of a sentence.
C)Use a comma to separate coordinate adjectives.
D)Use a comma to set off a parenthetical element in the sentence.