Galileo Galilei observed that the moon's surface is the not smooth.

Only a few centuries before Galileo had risked ridicule when, based on telescopic observations, he suggested that the moon's surface was not smooth. ... Nonetheless Galileo did not see perfection when he looked through his telescope at the moon in the early 17th century. He saw instead a surface that reminded him of earth.

before we can answer, we have to see the choices that are printed there with the question.   that's the only way we can point you to the correct one.

i think the answer is a, hope this is right, that would be my best guess.