Which of the following are valid json documents? Select all that apply.
A . {"a":l, "b":{"b":l, "c":"foo", "d":"bar", "e":[l,2,4]}}
B . {"city":"New York", "population", 7999034, boros:{"queens", "manhattan", "staten island", "the bronx", u "brooklyn"}}
C . {"name":"Fred Flintstone";"occupation":"Miner";"wife":"Wilma"}
D . { }
Answer: A,D