Final answer:
The barrier to communication that McFarland portrays is cultural and socio-economic barriers.
Step-by-step explanation:
Based on the information provided, the barrier to communication that McFarland portrays is cultural and socio-economic barriers. The passage mentions that miscommunication and ineffective communication occur when cultural and socio-economic barriers are present in the classroom setting. It also suggests that teachers are not prepared to effectively communicate with students of color, which can lead to communication breakdowns.