Consider a production possibility frontier witn $500$ tables is on the frontier. Which of the following are true?

i$)$ Production of $700$ books and $400$ tables is attainable but inefficient.

ii$)$ Production of $1000$ books and $600$ tables is unattainable.

iii$)$ Production of $500$ books and $1000$ tables is inside the frontier.

A$)$ ii and iii

B$)$ i and iii

C$)$ i$,$ ii and iii

D$)$ i and ii

E$)$ i only