What does perfectly inelastic demand imply about gains from trade and domestic consumers? Source: p 191, Question 9.7b, 9.7c, Principles of Microeconomics, 7 Ed, 2014, by NG Mankiw


  Consider a country that imports a good.
  True or false. Explain your answer.
  b) “If demand is perfectly inelastic, there are no gains
  from trade.”
  c) “If demand is perfectly inelastic, consumers do not
  benefit from trade.”


Please explain if this Best Answer is wrong? It claims that b) and c) are true. Yet my own work below shows a surplus of $+B$ after imports $\implies$ Gains from importing $\implies$ B and C are false.
Please feel free to correct my graph, but please also explain the intuition.
I wish to develop intuition, rather than be mechanically engrossed in graphs.
@VicAche this is incorrect. While the consumer may be willing to pay a large amount, consumer surplus is defined as the willingness to pay minus the price she pays. So if the willingness to pay is infinite as you correctly asserted, then the consumer surplus is also infinite. See my answer to this question.