Sentence Correction

While larger banks can afford to maintain their own data-processing operations, many smaller regional and community banks are finding that the cost associated with upgrading data-processing equipment and with the development and maintenance of new products and technical staff are prohibitive.
A. cost associated with
B. costs associated with
C. costs arising from
D. cost of
E. costs of

how to choose between B and E?

My answer is B.

"...associated with upgrading..." is paralleled with "...with the development..."

Regards!