Among the members of the company lauded for their notable effort were those from the Midwest division who were either actively involved
in improving the customer service experience or developing new approaches to long term customer relationship management.(A)
in improving the customer service experience or
(Missing preposition) developing new approaches to long term customer relationship management.
(B)
in improving the customer service experience or
to develop new approaches to long term customer relationship management.
(C)
in improving the customer service experience or
in developing new approaches to long term customer relationship management.
(D)
to improve the customer service experience or
(Missing preposition) developing new approaches to long term management of customer relationship.
(E)
to improve the customer service experience or
to develop new approaches to long term customer relationship management.
To depicts movement/ action, placing one thing in other. for ex: He moved to USA last year
while In depicts the place one is already situated at. for ex- He lives in USA.
Here the Noun is already doing the verb, so "in" is better word in place of "To", because noun place is not changed.
Hence Answer is C