[单选题]The non-compete clause has been causing trouble for over 600 years.In 1414 an English court heard the case of John Dyer,an apprentice whose master had stopped him from plying his trade for six months.The judge was having none of it."The contract is contrary to common law,"he ruled.Individuals should be free to pursue the livelihood of their choice.That principle has been diluted in the intervening centuries-most countries give businesses some leeway to use non-compete clauses,whereby workers promise not to start or join firms that go head-to-head with their ex-employer.But their prevalence in America is striking Defenders of these agreements put forward several arguments.One is that non-competes encourage innovation by stopping rivals waltzing off with trade secrets;there is some evidence that levels of investnent are higher at firms where they are used.Another argument is that firms are less likely to train workers if newly skilled employees are able to up sticks and take what they have learned with them to arival.Again,research backs up this claim.a third argument is that firms and employees should be free to contract as they wish he counter-arguments are stronger.The prevalence of non-compete agreements is clear evidence that they are being used indiscriminately.roughly 15 of american employees without a college degree,and a similar share of those earning less than$40,000 a year,are bound by them.Burger-flippers and care-home workers do not have trade secrets to hawk.unp pigr The gains in investment and training must be set against the wider costs.In one study,in Michi-gan,researchers found that workers'job mobility fell by 8%when non-competes were allowed.When people cannot work for another employer who would value their skills,wage growth suffers,too,because people typically achieve the biggest bumps in their salary when they move firm.Non-competes are also associated with a decline in enterprise.One study found that the rate of entry of new firms into knowledge-intensive industries fell by 18 when non-compete clauses could more easily be enforced The costs spill over to all workers-even those who are not subject to non-competes.Young firms are disproportionately important for job growth,for example;if fewer firms are formed,it will affect everyone in the labour market.And non-competes can have a chilling effect even in places that do not Recognise them The drawbacks of non-compete clauses are all the more worrying because of today's business climate.The incentive to invest and train counts for less when,as now,the American economy suffers from a lack of competition.Non-competes are also more worrying when the balance of power between companies and employees are already skewed.The spread of mandatory-arbitration clauses in employment contracts and the decline of trade unions are both signs of that imbalance What is the author's attitude toward the non-compete clause?
A.Appreciative
B.Cautious
C.Ambiguous
D.Critical