Answer:
B. What have been the effects of state bans on texting and driving
Explanation:
If the answer of any question is in a single word like 'yes' or 'no' then its is said to be close ended question.
On the other hand if the answer of any question is in several words and it cannot be answered in yes or no then such questions are open ended questions.
Among the given options all the questions can be answered in one word except the second one. In this question one has to explain the effects of state bans on texting and driving.
Therefore, B is an example of open - ended question.