Question

water on mars
like earth, mars contains plenty of volcanoes, and also like earth, most volcanoes on the red planet spew lava. however, many space scientists believe that mars may also have another type of volcano: one that gushes mud from its opening.
mud volcanoes are not a new phenomenon, and they exist in various places on our planet, including the oceans floors. what makes mars mud volcanoes so interesting is that they are a strong signal for the presence of water.
the possibility of water deposits on mars has intrigued scientists for some time because a water source would be required prior to any permanent human habitation. todays astronauts bring water with them for missions, but this would prove challenging on a lengthy mission to mars.
with future research into other water sources, such as a potential underground lake, scientists are hopeful that a mission to mars may soon be possible—perhaps only some ten years away. explorers on these missions are very likely to seek out and confirm the existence of mud volcanoes and the lake, which is believed to be some twelve miles across.

which choice makes the sentence most grammatically acceptable?
select one answer
a no change
b years
c years
d yearss

Explanation:

The sentence in question is "perhaps only some ten years' away". We need to determine the correct possessive or plural form. "Years" is the plural of "year", and when indicating the distance in terms of years (a plural noun acting as an adjective - like phrase here), the correct form is the plural "years" without an apostrophe (since we are not showing possession in the traditional sense but just the plural noun modifying "away"). Option A is "No Change" which is incorrect as the original has an apostrophe. Option C is "year's" (singular possessive) which is wrong. Option D is "years's" which is an incorrect plural possessive form. So the correct option is B.

Answer:

B. years