Context: Janet leaves a glass jar of cold tea outside in full sunlight. When she goes to get it, she notices that the tea is warm. She wonders what factors affect how warm a liquid gets from sitting in the sunlight. So, she decides to design an experiment. She has the following supplies available:
two identical glass jars
two jar lids
tap water
a measuring cup
two thermometers
Using only these supplies, which question can Janet investigate with an experiment?
A. When placed in the sun, will eight ounces of water in a glass jar or eight ounces of water in a plastic cup get warmer?
B. When placed in the sun, will eight ounces of water in a closed jar or eight ounces of water in an open jar get warmer?
C. Will eight ounces of carbonated water or eight ounces of tap water get warmer when placed in a jar in the sun?
Select the correct answer from the provided options and reply with the letter associated with it.

B