_ refers to the inconsistency or variations found in human performance.

I agree MR, Emad Muhammad.

_ refers to the inconsistency or variations found in human performance.

 c. heterogeneity.

>>>>>>>>>>>>> c. heterogeneity. >>>>>>>>>>>>>>>>

I would go with option ------------C

Agree with experts...........

answer C __________ heterogeneity

C.........................................................

c. heterogeneity...............................................................

Heterogeneity is quality of being different. So it represents inconsistency and variation found in human performance.  

Answer option ______________c

c. heterogenity is right answer ................................