Noting that the company's network is vulnerable to viruses and spyware, the consultant has urged Infotech to upgrade its protection software, institute new policies for exchanging sensitive information, assembling a special team of information technology specialists to manage network security protocols.

a) assembling a special team of information technology specialists to manage
b) assembling a special team of information technology specialists for managing
c) assembling a special team of information technology specialists that manages
d) and assemble a special team of information technology specialists to manage
e) and assemble a special team of information technology specialists for managing

The OA is d, but I had marked as E, considering For managing being parallel to for exchanging. Can someone please explain why to manage is correct and why for exchanging and for managing not paralle.

It is a parallelism issue, but it's a different set of terms that want to be parallel.

We have:
The consultant has urged Infotech to:
upgrade its protection software,
institute new policies for exchanging sensitive information,
assembling a special team of information technology specialists to manage network security protocols.

So upgrade, institute, and assemble want to be in the same format -- they all form the "list" of things Infotech has been urged to do.
We need an "and" before assemble, since it's the final piece in the series.
The "to manage" versus "for managing" is idiomatic, really.
It is preferable to say "specialists to manage protocols" rather than "specialists for managing protocols."
In the same vein, we would say "He is the expert hired to analyze data" rather than "He is the expert hired for analyzing data."

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