Read the following passage and questions, then choose the right answer from options, the answer should be one of A, B, C, D.

<passage>:
Every boy should be able to whistle, except, of course, Martians. But this one did! him . this particular little boy's whistling. Or, rather, there were two The first was that he was a Martian little boy. You could be very sure of that, for Earth little boys have earlobes while Martian little boys "'The Calm'," he said in a sober, little-boy voice. "The what little boy. When he was almost out of sight, I took off after him, wondering. The house he went into was over in that crumbling section which forms a curving boundary line, marking the limits of those frantic and ugly original mine-workings made many years ago by the early colonists. It a house and as long as a fisherman's alibi, of pure— pure , mind part, the mining shacks so hastily thrown up were only fever scars of a sickness long gone and little remembered. A few of the houses were still occupied, like the one into which the Martian boy had just disappeared. So his mother How had it been possible for her to teach, and for him to whistle? All Martians are as tone-deaf as a bucket of lead. you at all. I didn't know you lived here and I don't know who you are. I'm not even interested in who you are. It's the little boy who just went in here that I was interested in. The little Martian boy, I mean." to somewhere else in the house. Nowhere did I see the little boy. I "What about him?" she whispered. little boy went by me a while ago and he was whistling. He whistles She said one word only: "Well?" "Nothing," I answered. "Except that Martians are supposed to be hearing. So when I heard this little boy, and saw he was a Martian, and "There isn't any Martian lady." "There has to be, doesn't there?" I said it with little sharp prickers on the words. But she did, too: " Does there? " Her eyes were telling me that the little Martian boy wasn't a little Martian boy at all, that he was cross-breed, a little chap who had a Martian father and a human, Earthwoman mother. compared to a human male the Martian isn't anything you'd want around the house. I finally said: "So that is why he is able to whistle." inside her. "There isn't anything to be ashamed of," I said gently. "Back on Earth somewhere and intermarried plenty since." She nodded. Somehow her eyes didn't look defiant any more. "Where's his father?" I asked. luxurious living she was doing—at least not lately. "Look," I said suddenly. "Would you like to go home to Earth? I could fix—" woodwork stung my flinching cheeks. I shrugged and turned around and went down the steps. "And that is the His chuckle was a lewd thing, a thing usually reserved—if it ever was reserved at all—for the mens' rooms of some of the lower class dives. And then he stopped chuckling and frowned instead and said complainingly: "So?" he said. "Wanted, isn't he?" He nodded. "But a lot of good that'll do. He's holed up somewhere back on Earth." "No," I said. "He's right here. I just saw him." " I had idly listened to a little half-breed Martian boy whistling part Not finding him wasn't especially alarming. What was alarming, though, was not finding the Earthwoman and her little half-breed Martian son when I went back to the tumbledown shack where they lived. It was empty. She had moved fast. She hadn't even left me a note saying good-by. That night I went into the Great Northern desert to the Haremheb Reservation, where the Martians still try to act like Martians. It was Festival night, and when I got there they were doing the dance to the two moons. At times like this you want to leave the Martians The huge circle fire was burning and the dance was in progress. Briefly, this can be described as something like the ceremonial dances put on centuries ago by the ancient aborigines of North America. There was one important exception, however. Instead of a central fire, the Martians dig a huge circular trench and fill it with dried roots of the belu tree and set fire to it. Being pitch-like, the gnarled fragments burn for hours. Inside this ring sit the spectators, and in the exact center are the dancers. For music, they use the drums. The dancers were both men and women and they were as naked as Martians can get, but their dance was a thing of grace and loveliness. For an instant—before anyone observed me—I stood motionless and watched thought before, that this is the one thing the Martians can still do beautifully. Which, in a sad sort of way, is a commentary on the way things have gone since the first rocket-blasting ship set down on these purple sands. The Martian turned, went away from the half-light of the circle. He led Wahanhk is an old Martian. I don't think any Martian before him has the appearance of being done deliberately by a Martian sand-artist. "Not necessarily," I said. "I'm not here for trouble. I know as well as you do that, before tonight is finished, more than half of your men took a Martian for a husband." "I met her little son," I went on. "A little semi-human boy with other side, a little Martian boy who whistles." it was simply blank. "They disappeared from the shack they were living in," I said. "They went in a hurry—a very great hurry." That one he didn't answer, either. "I would like to know where she is." "Why?" His whisper was brittle. "She's not in trouble," I told him quickly. "She's not wanted. Nor her child, either. It's just that I have to talk to her." she might know him." "This one is wanted "Murder." He spat the word. "But not for the murder of a Martian, eh? Martians are not that important any more." His old eyes hated me with rolling out a lively tempo now, a tempo you could put music to. He said at last: "I do not know where the woman is. Nor the child." the words were out of his mouth, they were whipped in again on a drawn-back, great, sucking breath. For, somewhere outside, somewhere near that dancing circle, in perfect time with the lively beat of the cheese. "In your teeth, Wahanhk! Right in your teeth!" only bores a Martian. circle and the dancers within, and, too, I suppose, to her small son who was somewhere in that circle with them, whistling. She leaned Card. Assuming you know what it means, I'm asking you where he is." "Why should I care about an Earthman? My husband was a Martian. And he's dead, see? Dead. Just a Martian. Not fit for anything, like all Martians. Just a bum who fell in love with an Earthwoman and had the said to me, "But not for the murder of a Martian, eh? Martians are not that important any more." What I said then probably sounded as weak as it really was: "I'm sorry, kid. But look, just staking out in that old shack of yours and trying after it. For us. For the three of us." Next day I followed the little boy. He left the reservation in a cheery It was desert country, of course. There wasn't any chance of tailing him without his knowledge and I knew it. I also knew that before long he'd know it, too. And he did—but he didn't let me know he did until I knew where he was going. There could only be one place, of course—the city of Deimos and Phobos. Other than that he had no choice. And I thought I knew the reason for his going. himself of finding the killer of his daddy.

<question>:
How does the narrator know that the little boy and his mother are with the Martians at the fire?

<options>:
A He hears the boy whistling.
B He follows them there.
C Wahanhk tells him where to find them.
D They live there.

<answer>:

A