A student measured the diameter of a small steel ball using a screw gauge of least count $0.001 \mathrm{cm}$. The main scale reading is $5 \mathrm{mm}$ and ${25}^{th}$ division of circular scale coincides with reference line. If screw gauge has a zero error of $-0.004 \mathrm{cm}$, the correct diameter of the ball is

• A

  $0.053 \mathrm{cm}$
• B

  $0.525 \mathrm{cm}$
• C

  $0.521 \mathrm{cm}$
• Correct answer
  D

  $0.529 \mathrm{cm}$

Hence, the correct answer is option: 'D'.