Triple

Target entity: Riemann–Siegel phase function
Context triple: [Riemann–Siegel theta function, alternativeName, Riemann–Siegel phase function]

• A. Riemann–Siegel formula
  The Riemann–Siegel formula is an asymptotic expression that efficiently approximates the Riemann zeta function on the critical line, playing a key role in the numerical study of its zeros.
• B. Riemann–Siegel theta function chosen
  The Riemann–Siegel theta function is a special function that appears in the study of the Riemann zeta function, used to express its values on the critical line in a form suitable for high-precision numerical computation.
• C. Riemann zeta function
  The Riemann zeta function is a complex-valued function central to analytic number theory, whose properties—especially the distribution of its zeros—are deeply connected to the distribution of prime numbers.
• D. Riemann xi function
  The Riemann xi function is an entire, symmetrized version of the Riemann zeta function that encodes its nontrivial zeros and plays a central role in the study of the Riemann Hypothesis and related analytic number theory.
• E. Chebyshev functions
  Chebyshev functions are arithmetic functions in number theory that encode information about the distribution of prime numbers and play a key role in analytic approaches to the prime number theorem.
• F. None of above.
• G. Unsure - the case is ambiguous/there is not enough information to decide.