During a tensile test on a specimen of 1 cm cross-section, maximum load observed was 8 tonnes and area of cross-section at neck was 0.5 cm2. Ultimate tensile strength of specimen is___________________?
A. 4 tonnes/cm2
B. 8 tonnes/cm2
C. 16 tonnes/cm2
D. 22 tonnes/cm2
E. none of the above