Suppose that Y = C + I + G + X - Z. Which of the following can be illustrated by a rightward shift of the AD curve?

(a) Increased technological innovation and political stability.

(b) A boom in major economies such as China, which are South Africa's major trading partners.

(c) Depreciation of the local currency against the world's major currencies due to speculation.

a.

Only (a) is correct

b.

Only (c) is correct

c.

All (a), (b) and (c) are correct

d.

Only (a) and (b) are correct

e.

Only (b) and (c) are correct