Retail price difference between $16GB$ Ipad and $32GB$ lpad is used to illustrate which of the following?

Apple's marketing skills

II$.$ The price difference is much higher than the cost to add the additional $16GB$

III. Apple's success in convincing customers to pay premium prices for its products

Only statement I is true

Only statement II is true

Only statements I and II are true

Only statements II and III are true

Statements $1,$ II$,$ and III are true.