下列字符定义正确的是_____
A.
<label aria-describedby="status_907e12661c59e6b62959_2_1">"R"</label>
B.
'R'
C.
'ab'
D.
<input type="radio" name="input_907e12661c59e6b62959_2_1" value="choice_3">“ab”
正确答案是B