Please select the most similar patent number from A, B, C and D. Which number is?
An infant bed comprises a first bottom board (1), a second bottom board (2), a first side board (3), a second side board (4), a third side board (5), a first guardrail (7), a second guardrail (8), a first bed board (9), a second bed board (10), a shelf board (11), a rack shaft (12), and a separation board (13). The components of the infant bed can be disassembled and reassembled into a study desk, a closet and a shelf, thereby implementing various use functions of an infant bed, prolongs the service life of an infant bed, and reducing the domestic cost.
A: A rehabilitation massage bed comprising ironic balls (1), a first bed board (3), a second bed board (4), a magnetic rod (5), a third bed board (6), a controller (7), and a massage bed body (9). The first bed board, the second bed board, the third bed board, and the controller are all provided inside the massage bed body; the first bed board is provided above the second bed board; the second bed board is provided above the third bed board; a plurality of round holes are formed in the first bed board, and an ironic ball is provided in each round hole; the magnetic rod is provided between the second bed board and the third bed board; the controller is electrically connected to the magnetic rod and is used for controlling the magnetic rod to generate a magnetic force and move on the third bed board. The massage bed changes the direction of a magnetic force applied to the ironic balls by means of the movement of the magnetic rod, thereby driving the ironic balls to rotate, so as to massage a user. Because there is no circuit connection structure between the magnetic rod and the ironic balls, the structural complexity of the massage bed is reduced, and the service life of the massage bed is prolonged.
B: Provide is a single-motor electrically powered bed, the single-motor electrically powered bed comprising: a bed board (1), a frame (2), a slide assembly (3), a first connecting-rod mechanism (4), and a drive assembly (5); the bed board (1) comprises: a first bed board (11) and a second bed board (12), one end of the first bed board (11) being hingedly connected to one end of the second bed board (12); the second bed board (12) is slidably connected to the frame (2) by means of the slide component (3), the two ends of the first connecting-rod mechanism (4) are hingedly connected to the first bed board (11) and the frame (2), respectively, and the first bed board (11) can be raised and lowered by means of the drive assembly (5). The single-motor electrically powered bed needs only one drive assembly (5) to drive all of the bed boards (1) to move, adjust the position and height of the human body, and achieve the lifting and lowering function of the electrically powered bed, and saves costs and reduces the volume and quality of the electrically powered bed; the human body follows the movement of the bed board (1), moving closer to one end of the bed body, maintaining a straight horizontal distance between the human body and the object it is facing.
C: An infant bed comprises: an upper fencing frame (1) and a lower fencing frame (2), support fames being disposed at right and left sides of the upper fencing frame (1) and the lower fencing frame (2), the support frame comprising a vertical rod (3), an upper end of the vertical rod (3) being detachably connected to the upper fencing frame, a middle portion of the vertical rod (3) being detachably connected to the lower fencing frame (2) by a connection part (4), a bottom portion of the vertical rod (3) being connected to a swinging rod (5), a detachable middle fencing frame or bed plate (6) being disposed between the upper fencing frame (1) and the lower fencing frame (2), and a changing station (7) used to change diapers for babies being placed on the upper fending frame (1). The infant bed is of a proper structure, and is convenient to fold, store, and carry. Moreover, the infant bed can be used as a children shaker when the bed plate is placed on the middle fending frame, and when the middle fending frame is detached and a bottom plate is placed on the lower fending frame, the infant bed becomes a place where children plays.
D: A foldable ultra-light steel prefabricated house. A bottom board (1) is connected to a house body (2); the house body (2) comprises a first side board (3), a second side board (4), a third side board (5), and a fourth side board (6); the first side board (3) and the third side board (5) are structurally symmetrical; the second side board (4) and the fourth side board (6) are structurally symmetrical; the first side board (3) is formed by connecting a first wall board (7) to a first roof board (8); the second side board (4) is formed by connecting a second wall board (9) to a second roof board (10); the second wall board (9) comprises a second upper wall board (11) and a second lower wall board (12) that are hingedly connected; the bottom board (1) consists of a first bottom board (13) and a second bottom board (14) of the same size; the first bottom board (13) is hingedly connected to the second side board (4); the second roof board (10) and the second upper wall board (11) are hingedly rotated to form an upper foldable board (15) in the same plane; the second lower wall board (12) and the first bottom board (13) are hingedly rotated to form a lower foldable board (16) in the same plane; the upper foldable board (15) and the lower foldable board (16) are the same in shape and size. The prefabricated house does not need to be disassembled, can be folded, and occupies a small space after being folded.
Answer: C