Question

what causes air masses to move?
when prevailing westerlies shift directions and move toward the west.
weather conditions change rapidly to produce storms.
a collision takes place between two natural wind patterns.
long, narrow bands of wind blow in the upper atmosphere.

Explanation:

To determine the cause of air mass movement, we analyze each option:

• The first option is incorrect because prevailing westerlies generally move toward the east, not west.
• The second option describes storm formation, not what causes air masses to move.
• The third option about wind pattern collisions is not the primary cause of air mass movement.
• The fourth option refers to jet streams (long, narrow bands of wind in the upper atmosphere), which are a major factor in moving air masses by steering them.

Answer:

D. Long, narrow bands of wind blow in the upper atmosphere. (Note: Assuming the options are labeled A - D in order, with the last option being D. If original labels differ, adjust the identifier but keep the text: "Long, narrow bands of wind blow in the upper atmosphere.")