The productivity of labour does not depend only o its own effort and efficiency, but also on I the level of technical knowledge II. the quality of other factors III. racial qualities which allow persons from certain races to have good physique and be very active . Which of the above statements is /are correct?
-
A.
I only -
B.
I and II only -
C.
I and III only -
D.
II and III only -
E.
III only