Triple

Target class: pseudo-Riemannian metric
Context triple: [Minkowski metric η_{μν}, instanceOf, pseudo-Riemannian metric]

• A. pseudo-Riemannian manifold chosen
  A pseudo-Riemannian manifold is a smooth manifold equipped with a nondegenerate, symmetric metric tensor of arbitrary signature that allows measurement of lengths and angles, including those with indefinite sign as in spacetime geometry.
• B. Lorentzian manifold
  A Lorentzian manifold is a smooth manifold equipped with a metric tensor of signature \((-+\cdots+)\) (or its variants) that models spacetime in general relativity by distinguishing timelike, spacelike, and null directions.
• C. pseudometric
  A pseudometric is a function that assigns a nonnegative real number as a "distance" between any two points in a set, satisfying all the axioms of a metric except that distinct points are allowed to have zero distance.
• D. curvature tensor
  A curvature tensor is a multilinear mathematical object in differential geometry that measures how much a space (or manifold) deviates from being flat by quantifying the failure of vectors to return to their original direction after parallel transport around infinitesimal loops.
• E. differential geometric object
  A differential geometric object is a mathematical entity, such as a manifold, tensor, or connection, defined on smooth spaces and characterized by properties that are invariant under smooth coordinate transformations.
• F. None of above.