韩某因涉嫌盗窃而被提出公诉，案件起诉到法院后，该案由员额法官赵某主审。赵某发现韩某是其初中同学，初中时两人经常打架，但初中毕业之后两人已多年不联系。关于本案处理，下列哪一说法是正确的

A．An economy can produce at any point inside the production possibilities frontier, but not on or outside the frontier.
B．An economy can produce at any point on or inside the production possibilities frontier, but not outside the frontier.
C．An economy can produce only on the production possibilities frontier.
D．An economy can produce at any point inside or outside a production possibilities  frontier.