How is the Vicker‚Äö√Ñ√∂‚àö√ë‚àö¬•s hardness number defined as?$

How is the Vicker‚Äö√Ñ√∂‚àö√ë‚àö¬•s hardness

1.	How is the Vicker‚Äö√Ñ√∂‚àö√ë‚àö¬•s hardness number defined as?$
A.	1.8544PD<sup>2</sup>
B.	1.8544P 1/D<sup>2</sup>
C.	8.544P 1/D<sup>2</sup>
D.	8.544PD<sup>2</sup>
Answer» C. 8.544P 1/D<sup>2</sup>