Given the task definition and input, reply with output. You are given a short paragraph, a question and two choices to answer from. Choose the correct answer based on the paragraph and write the answer(not the key).

Paragraph: Differences in air pressure over the surface of the Earth result in wind. The greater the differences in air pressures, the stronger the wind.
 Question: Lana is noting that the wind lately has been very weak. Lana can now tell that the air pressures over the Earth's surface have had differences that are 
 Choices: A)greater 
B)lesser
lesser