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: Warm water cant hold as much dissolved oxygen as cool water, so an increase in the temperature of water decreases the amount of oxygen it contains.
 Question: Mary is taking measurements of the amount of oxygen in samples of water. If she measured the total levels of dissolved oxygen in a sample at 70 degrees fahrenheit and compared it to a sample at 80 degrees fahrenheit, which would contain more dissolved oxygen? 
 Choices: A)80 degrees fahrenheit 
B)70 degrees fahrenheit
70 degrees fahrenheit