Please help me on these:

12. The natural factor limiting development of the West is the availability of
a. water
b. land
c. mineral deposits
d. natural vegetation
I'm sure it's not B.
I'm stuck between water and mineral deposits.
here's what i read in my book:
'The abundance or scarcity of water is the major factor shaping the West's natural vegetation, economic activity, and population density. Most of the West has a semiarid or arid climate. In dry areas the natural vegetation consists of short grasses, hardy shrubs, sagebrush, and cactus. In contrast, the western side of the cordillera generaglly receives adequate rainsfall and contains rich decidious and coniferous forests at lower elevations. ...Beneath the jagged peaks of the Rocky Mountains and the Sierra Nevada lies an immense storehouse of minerals-gold, silver, uranium, an other metals. ...Most of the region's welath was deep underground, out of reach of the average prospector. ..Along with the prospecstors came enterprising people who set up business to provide goods and services to the miners. The population of the West grew rapidly..'

also,
10. All of the following statements about the Great Lakes and the Mississippii River system are true EXCEPT
a. they aided the growth of industry in the Midwest
b. they are still important trade routes today
c. cities connected by this transportation networdk are hoome to heavy manufacturing
d. they have ehlped the region become the nation's center ofbusiness and finance

it's not A, because that is true
i think it might be D

'Many Midwestern cities are located on the shores of the Great Lakes or along major rivers. Water transporation aided the growth fo heavy industreis, sucha s the manufacture of automobiles and machinery. Over 600 million tons of goods travel through the Mississippi River system each year. With the growht of the Us railway system, thougands of railroad cars were pulling into Chicago every eyar. Freight cars brought millions of bushels of grain and ehad of livestock from fars fartehrwest. In chicago, the grain was processed and thelviestock slaughtere.d The meat and grain were then shipped eastward by railroad...'

thanks

3 answers

12. The answer is found in the first sentence -- aka the topic sentence -- in the paragraph from your book.

13. Correct.

thank you very much!

You're welcome.