Which of the following is not a barrier to entry?

Lesley buys 6 cappuccinos per week when her income is $900 per week and buys 8 cappuccinos per week when her income is $1100 per week. For Lesley, cappuccinos are a(n) ________ good

A) normal B) luxury C) inferior D) essential E) substitute

In the above figure, what is the profit at the profit-maximizing output level?

A) $70 B) $2 C) $20 D) $10