The term call into question is identified in base64 scheme by the sequence Y2FsbCBpbnRvIHF1ZXN0aW9u, while the MD5 signature is equal to ad2c2526eae7f6329500113ac23a952c. The ASCII encoding of call into question in hexadecimal notation is 63616c6c20696e746f207175657374696f6e.