A.I. Explanation:

Option 1: "Technology becomes the important factor in online education."

Explanation: The text emphasizes that 2020 marked a significant shift in education due to the reliance on technology for delivering lessons. It states that technology has taken center stage, highlighting its crucial role in the educational transformation during this period. This aligns with the main idea that technology is a vital factor in online education.

Option 2: "Students can’t study without smartphones."

Explanation: While the text mentions that many students were deprived of lessons due to a lack of devices, it does not state that students cannot study without smartphones specifically. This option presents a narrow interpretation of the broader issue of access to technology.

Option 3: "Teachers can’t prepare lessons well for online courses."

Explanation: The text discusses the challenges teachers faced with technology but does not claim that they cannot prepare lessons well. It mentions the level of preparedness and competence of teachers, indicating variability rather than a blanket statement about their inability to prepare lessons.

Option 4: "Students must do their lessons via websites."

Explanation: The text states that students were doing lessons via websites like Zoom, but it does not imply that this is the only way they can study. This option is too absolute and does not capture the nuances of the text regarding the various factors affecting students' access to education.