A.
{"userName":"马云","userAge":51},{"userName":"马化腾","userAge":44}
B.
["userName":"马云","userAge":51,"userName":"马化腾","userAge":44]
C.
[{"userName":"马云","userAge":51}],[{"userName":"马化腾","userAge":44}]
D.
[{"userName":"马云","userAge":51},{"userName":"马化腾","userAge":44}]