单选题

以下代码执行的结果是（）vararr=[{old:'old'},['old...

Question

以下代码执行的结果是（）

var arr = [{old: 'old'}, ['old'], 'old']
var new_arr = arr.concat()
arr[0].old = 'new'
arr[1][0] = 'new'
console.log(arr)
console.log(new_arr)

A. [{old: 'old'}, ['old'], 'old'], [{old: 'old'}, ['old'], 'old']

B. [{old: 'old'}, ['old'], 'new'], [{old: 'new'}, ['new'], 'new']

C. [{old: 'new'}, ['new'], 'new'], [{old: 'new'}, ['new'], 'new']

D. [{old: 'new'}, ['new'], 'old'], [{old: 'new'}, ['new'], 'old']