Suppose that one of the following events occurs:

(i) The price of wool rises.

(ii) The price of sweaters falls.

(iii) A close substitute for wool is invented.

(iv) A new high-speed loom is invented.

Which of the above events increases or decreases (state which)

a. The demand for wool?

b. The supply of wool?

c. The quantity of wool demanded?

d. The quantity of wool supplied?