Question

read the paragraph. then, add the best topic sentence.
for example, glaciers can wear away the sides of mountains by scraping against them as they float past, creating valleys. they can also form small lakes when a piece of glacier breaks off and then melts. some glaciers even transport huge boulders from one place to another.
glaciers can change the shape of the land they move through.
some valleys, like yosemite valley, were carved by glaciers.
wind and running water can both wear away rock.

Explanation:

The paragraph focuses on how glaciers change the land (creating valleys, lakes, transporting boulders). The topic sentence should introduce this main idea. "Glaciers can change the shape of the land they move through" captures the overall theme of glacier - induced landform changes, while the other options are either about other agents (wind, water) or a specific example (Yosemite Valley).

Answer:

Glaciers can change the shape of the land they move through.