$A$ student performs an experiment for the determination of $g = \frac{4 \pi^{2} \ell}{T^{2}}$. Given $\ell = 1 \, m$,the student commits an error of $\Delta \ell$. For $T$,the student measures the time of $n$ oscillations using a stopwatch with a least count of $\Delta T$ and commits a human error of $0.1 \, s$. For which of the following data will the measurement of $g$ be the most accurate?

• A
  $\Delta \ell = 5 \, mm, \Delta T = 0.2 \, s, n = 10$
• B
  $\Delta \ell = 5 \, mm, \Delta T = 0.2 \, s, n = 20$
• C
  $\Delta \ell = 5 \, mm, \Delta T = 0.1 \, s, n = 10$
• D
  $\Delta \ell = 1 \, mm, \Delta T = 0.1 \, s, n = 50$