Please help me on this question:

Question

33. Wind and water alter the Earth's sufrface by
a. blowing away soil and eroding soft rocks
b. eroding coastlines
c. carving deep gorges
d. all of the above

I read about this a long time ago, so I don't even remember where it is in my book. Please, do help me.
Thankyou

Answer 1

Look up erosion in the index of your book.

Or -- Google erosion.

Answer 2

is it A?

Answer 3

How do you think the Grand Canyon was formed?

Answer 4

I do remember in FFA a poster of the Grand Canyon, with the caption " This could have been prevented with contour plowing".

http://en.wikipedia.org/wiki/Contour_plowing