Ramanujan’s last letter to G. H. Hardy

Target entity: Ramanujan’s last letter to G. H. Hardy
Context triple: [mock theta functions, introducedIn, Ramanujan’s last letter to G. H. Hardy]

• A. Ramanujan’s lost notebook
  Ramanujan’s lost notebook is a posthumously discovered collection of Srinivasa Ramanujan’s final mathematical formulas and insights, many of which were decades ahead of their time in number theory and q-series.
• B. Hardy–Ramanujan asymptotic formula
  The Hardy–Ramanujan asymptotic formula is a landmark result in number theory that gives an approximate expression for the partition function p(n), describing how the number of integer partitions of n grows rapidly with n.
• C. Ramanujan partition congruences
  Ramanujan partition congruences are remarkable number-theoretic results discovered by Srinivasa Ramanujan that describe surprising modular patterns in the partition function, such as specific arithmetic progressions where the number of integer partitions of an integer is divisible by a given prime.
• D. Ramanujan’s sum
  Ramanujan’s sum is a number-theoretic function introduced by Srinivasa Ramanujan, expressing certain periodic arithmetic functions as finite trigonometric sums over primitive roots of unity.
• E. Three Pearls of Number Theory
  Three Pearls of Number Theory is a classic mathematical text that presents three elegant and accessible problems in number theory, illustrating deep ideas through simple, beautifully explained examples.
• F. None of above. chosen
• G. Unsure - the case is ambiguous/there is not enough information to decide.

Target entity: Ramanujan’s last letter to G. H. Hardy
Target entity description: Ramanujan’s last letter to G. H. Hardy is a famous 1920 correspondence in which the mathematician Srinivasa Ramanujan outlined his mysterious mock theta functions, profoundly influencing later developments in number theory and modular forms.

• A. Ramanujan’s lost notebook
  Ramanujan’s lost notebook is a posthumously discovered collection of Srinivasa Ramanujan’s final mathematical formulas and insights, many of which were decades ahead of their time in number theory and q-series.
• B. Hardy–Ramanujan asymptotic formula
  The Hardy–Ramanujan asymptotic formula is a landmark result in number theory that gives an approximate expression for the partition function p(n), describing how the number of integer partitions of n grows rapidly with n.
• C. Ramanujan partition congruences
  Ramanujan partition congruences are remarkable number-theoretic results discovered by Srinivasa Ramanujan that describe surprising modular patterns in the partition function, such as specific arithmetic progressions where the number of integer partitions of an integer is divisible by a given prime.
• D. Ramanujan’s sum
  Ramanujan’s sum is a number-theoretic function introduced by Srinivasa Ramanujan, expressing certain periodic arithmetic functions as finite trigonometric sums over primitive roots of unity.
• E. Three Pearls of Number Theory
  Three Pearls of Number Theory is a classic mathematical text that presents three elegant and accessible problems in number theory, illustrating deep ideas through simple, beautifully explained examples.
• F. None of above. chosen