On Election Day, TV news network Houston News One is trying to project the 2018 Texas election results. They send pollsters to 400 voting places throughout the state to survey people before they cast their vote. Which type of poll is the news network conducting?

entrance poll

Explanation:

Based on the information provided within the question it seems that the type of poll that the news network is conducting is an entrance poll. This refers to asking question (poll) to people outside of the voting center before they enter to place their vote as opposed to exit poll which is done after the individual has placed their vote.