单项选择题
A．The "Post Paid" Error B．The Two Penny Blue C．A Rare Stamp D．How Mauritius Became Famous
A．the One Penny Orange-Red B．a correctly printed'1847 stamp C．the Two Penny Blue D．both A and C
A．there are few others like it B．there are no errors on the stamps C．a mistake is made in the ,printing D．both A and C