Answer: Exit poll
Step-by-step explanation:
An exit poll is a type of poll conducted immediately voters exit the polling units, an exit poll ask whom a voter actually casted their vote for. Dutch sociologist Marcel Van Dam claimed to have invented and implemented exit poll on February 15 1967 during the Dutch legislative elections .
Exit polls helps to find out about whom voters voted for since the votes are casted anonymously, it is also used to determine the success of a political campaign. Exit polls have very low scientific rigor.