human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "lower bounds on the dilation of plane spanners"
  Abstract: (I) We exhibit a set of 23 points in the plane that has dilation at least $1.4308$, improving the previously best lower bound of $1.4161$ for the worst-case dilation of plane spanners. #R##N#(II) For every integer $n\geq13$, there exists an $n$-element point set $S$ such that the degree 3 dilation of $S$ denoted by $\delta_0(S,3) \text{ equals } 1+\sqrt{3}=2.7321\ldots$ in the domain of plane geometric spanners. In the same domain, we show that for every integer $n\geq6$, there exists a an $n$-element point set $S$ such that the degree 4 dilation of $S$ denoted by $\delta_0(S,4) \text{ equals } 1 + \sqrt{(5-\sqrt{5})/2}=2.1755\ldots$ The previous best lower bound of $1.4161$ holds for any degree. #R##N#(III) For every integer $n\geq6 $, there exists an $n$-element point set $S$ such that the stretch factor of the greedy triangulation of $S$ is at least $2.0268$.

Connected through hyperedge HE-1 (induced by source paper "drawing graphs as spanners"):
  with members:
    - "on plane constrained bounded degree spanners"
    - "optimal monotone drawings of trees"
    - "strongly monotone drawings of planar graphs"
    - "on planar greedy drawings of 3 connected planar graphs"
    - "on monotone drawings of trees"
    - "recognition and complexity of point visibility graphs"
    - "on self approaching and increasing chord drawings of 3 connected planar graphs"
    - "increasing chord graphs on point sets"

Connected through hyperedge HE-2 (induced by source paper "sparse hop spanners for unit disk graphs"):
  with members:
    - "on geometric spanners of euclidean and unit disk graphs"

Connected through hyperedge HE-3 (induced by source paper "gabriel triangulations and angle monotone graphs local routing and recognition"):
  with members:
    - "optimal local routing on delaunay triangulations defined by empty equilateral triangles"
    - "increasing chord graphs on point sets"
    - "the stretch factor of the delaunay triangulation is less than 1 998"
    - "self approaching graphs"

Connected through hyperedge HE-4 (induced by source paper "towards plane spanners of degree 3"):
  with members:
    - "the stretch factor of the delaunay triangulation is less than 1 998"
    - "on geometric spanners of euclidean and unit disk graphs"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.CG(Computational Geometry)