The overall slackening of growth in productivity is influenced less by government regulation, although that is significant for specific industries like mining, than the coming to an end of a period of rapid growth in agricultural productivity.
(A) the coming to an end of
(B) the ending of
(C) by the coming to an end of
(D) by ending
(E) by the end of
slcakening of growth ... influenced less by X than by Y
A, B -out
D,E -- distorts the original meaning.
= coming to an end of period of rapid growth
D --> by ending period of rapid growth (means.. looks like someone ending period of rapid growth..)
E --> by the end of period of rapid growth ( means. ... end of period .. influencing slackending growth.. which looks awkard)
Go with C.
Your attitude determines your altitude
Smiling wins more friends than frowning