1.a)Which of the following factors influences demand?Provide Justification to support your answer.

I.consumer income;

II.prices of complement goods;

III.prices of substitute goods;

IV.the number of consumers

a)I and IV

b)II and III

c)I, III, and IV

d)I, II, III, and IV

b)Electric guitars and amplifiers are complement goods, and electric guitars and acoustic guitars are substitute goods. An increase in the price of amplifiers ______ the number of electric guitars consumers want to buy, while an increase in the price of acoustic guitars ______ the number of electric guitars consumers want to buy.

i.increases, decreases

ii.decreases, increases

iii.increases, increases

iv.decreases, decreases

Provide Justification to support your answer.