Use the table to answer the question.

Day Observations
1 sunny and warm
2 cloudy and rainy
3 drop in temperature
4 clear skies and cold temperatures
A student tracks the daily weather. The student’s observations are logged in the table. Which factor in the atmosphere best explains the student’s observations?

1. A warm air mass replaced a cold air mass.
2. A warm front moved into the area.
3. A cold front moved into the area.
4. High levels of moisture are contained within an air mass.

Based on the observations in the table, the factor in the atmosphere that best explains the student's observations is option 3: A cold front moved into the area. The change from sunny and warm on day 1 to cloudy and rainy on day 2 suggests the passage of a cold front, which typically brings cooler temperatures and cloudy/rainy weather conditions. The drop in temperature on day 3 and the clear skies and cold temperatures on day 4 also indicate the influence of a cold front.