Which aspect has not changed the face of american farms forests of giant redwood trees grow in

a) The aspect of decreased productivity has not changed the face of American farms.

Explanation:

Though the productivity of American farms has decreased with time owing to nutrition loss in soil and overuse of the land, the rate of cultivation doesn't seem to have changed. Despite decreased productivity, all the land that has been used for centuries is still being brought under cultivation regularly. To increase the productivity, it is necessary to give the agricultural lands the required time to regain the nutrition in the soil naturally. Unfortunately, this is not seen happening in American farms.

b) Forests of giant redwood trees grow in California.

Explanation:

The Redwood National and State Park is located in California adjacent to the western coast. It is spread over an area of about 562 sq. kilometers. It is mainly characterized by the presence of coastal mountains on which there are thousands of giant redwood trees that form a thick forest. The forest is home to great biodiversity which houses animals like Roosevelt elks, black-tailed deer, black bears, and mountain lions.