Answer:
The statement that is the most respectful and credible in supporting teen ownership and use of smartphones is:
News and information outlets such as Onlinecolleges.net report that 47 percent of students have used a mobile app for learning.
Step-by-step explanation:
A formal statement has to be composed by specific vocabulary and it should not use any kind of slang, about making it credible it is necessary to add trustworthy sources of information with well-defined data to fully support the idea, "News and information outlets such as Onlinecolleges.net report that 47 percent of students have used a mobile app for learning." is the best example of that from the four given options.