400
Which of the following statements about meteorite craters on Europa would be most consistent with both scientists' views?
A. No meteorites have struck Europa for millions of years.
B. Meteorites craters, once formed, are then smoothed or removed by Europa's surface processes.
C. Meteorites craters, once formed on Europa, remain unchanged for billion of years.
D. Meteorites frequently strike Europa's surface but do not leave any craters.
B is the best answer. Both scientists describe surface processes that smooth or remove meteorite craters. Scientist 1 says that the craters become smooth when liquid water oozes into the craters and then quickly freezes. Scientist 2 says the process is the result of the sublimation of ice.