In a tensile testing experiment on a specimen of 1 cm$$^2$$ area, the maximum load observed was 5 tonnes and neck area 0.25 cm$$^2$$. The ultimate tensile strength of specimenis

A

2.5 tonnes/cm$$^2$$

B

10 tonnes/cm$$^2$$

C

5 tonnes/cm$$^2$$

D

20 tonnes/cm$$^2$$