输出什么？

function getFine(speed, amount) {
  const formattedSpeed = new Intl.NumberFormat('en-US', {
    style: 'unit', unit: 'mile-per-hour'
  }).format(speed)

  const formattedAmount = new Intl.NumberFormat('en-US', {
    style: 'currency', currency: 'USD'
  }).format(amount)

  return `The driver drove ${formattedSpeed} and has to pay ${formattedAmount}`
}

console.log(getFine(130, 300))

A. The driver drove 130 and has to pay 300 B. The driver drove 130 mph and has to pay $300.00 C. The driver drove undefined and has to pay undefined D. The driver drove 130.00 and has to pay 300.00

答案： B

解析：

通过方法 Intl.NumberFormat，可以格式化任意区域的数字值。我们对数字值 130 进行 mile-per-hour 作为 unit 的 en-US 区域 格式化，结果为 130 mph。对数字值 300 进行 USD 作为 currentcy 的 en-US 区域格式化，结果为 $300.00.