Triple

Target class: obstruction to weak approximation
Context triple: [Brauer–Manin obstruction, instanceOf, obstruction to weak approximation]

• A. result in arithmetic geometry
  A result in arithmetic geometry is a theorem or proposition that connects number-theoretic properties of solutions to polynomial equations with the geometric structure of the varieties they define over arithmetic fields.
• B. curve over the rational numbers
  A curve over the rational numbers is an algebraic curve defined by polynomial equations with rational coefficients, considered together with its set of rational solutions and their arithmetic properties.
• C. technique in Diophantine geometry chosen
  A technique in Diophantine geometry is a systematic method or tool—often combining algebraic, geometric, and arithmetic ideas—used to study and solve equations with integer or rational solutions on algebraic varieties.
• D. result in metric Diophantine approximation
  A result in metric Diophantine approximation is a theorem that describes how well almost all real numbers (with respect to a given measure) can be approximated by rationals or other structured sets, typically quantifying the size or frequency of exceptional sets.
• E. theorem in metric number theory
  A theorem in metric number theory is a rigorous statement describing the behavior of number-theoretic objects (such as Diophantine approximations or distribution of sequences) for "almost all" real numbers with respect to a given measure, typically Lebesgue measure.
• F. None of above.