Tracking polls are significant because they:

a. can catch daily changes in public opinion that other polls cannot
b. are inexpensive to conduct
c. allow pundits to make predictions on election day
d. have caused the public to question the accuracy of polls
e. candidates devise their campaign strategy

The correct answer is A.

Explanation:

Remember that a tracking poll is used to measure attitudinal and behavioral changes in a target population using individuals surveys which allow researchers to know people's opinions and the changes presented over time.  

Option A

Explanation:

The main essence of tracking data is to catch, observe and identify changes or development of a particular data in question.

Tracking polls in this context, will give updates on changes depending on the time these updates are required. in other words, they can also be used to catch daily changes in the public opinion if they are required daily

b) to encourage free trade

they can increase to boost the enonomy.