Answer: provide a clearly expressed viewpoint.
Step-by-step explanation:
A thesis is the proposed answer to a research question, and it's finalized after the completion of the research.
Since the student's thesis is that "Parents should, if they choose, limit the amount of television their children are viewing", the best way to improve this thesis is to provide a clearly expressed viewpoint.
A clearly expressed viewpoint should be written which will buttress the point that the researcher is trying to make.