Choose the closest paraphrased version after the following sentence or the italicized part.
For a second Rudolf thought his host [the lighthouse keeper] might be joking; but the serenity of the other’s expression reassured him.
A.正确答案C... but Rudolf found from the old man’s expression that he was not serious.
B.... but Rudolf’s expression showed the old man that he was only joking.
C.... but the old man’s calm expression convinced Rudolf that he was not joking.
D.... but Rudolf looked peaceful, so the old man was sure that he meant what he said.
