AP English Language

The clear and focused thesis statement is: A."Smartphones have various effects on teenagers, such as affecting their communication skills, altering their sleep patterns, and impacting their schoolwork."

Explanation:

This thesis is clear and focused because:

1.It specifies a specific topic (smartphones and their effects on teenagers).

2.It identifies particular effects (communication skills, sleep patterns, schoolwork).

3.It gives clear direction for the essay by focusing on the impacts of smartphones on teenagers.

Why the other options are not clear and focused:

B."There are many problems in the world."