Final answer:
Tipping refers to a demographic change within a voting population sufficient to alter the political balance in a state. Therefore, the correct option is C.
Step-by-step explanation:
The term tipping in the context of political science refers to a demographic shift within a voting population that is substantial enough to affect election outcomes. The most accurate description of tipping is that it occurs when a group that is becoming more numerous over time grows large enough to change the political balance in a state. This can relate directly to changes in population such as an increase in a particular ethnic group within the electorate or the rising prominence of a societal group whose growth in numbers or shifts in political allegiance could significantly influence the direction of elections and party dominance.