By providing such services as mortgages

The bank is doing 2 things, providing services and staying. They are providing 4 services, thus you have a list "mortgages, loans, loans, and financial advice...." Can't be A or B. You need the and between the two things they do, namely providing and staying. Can't be C. Do you need the "by" or not? Yes, it's a parallelism, "By providing and by staying". The answer is E.

vishalwin wrote:No clue here. I am very confused how to eliminate. Please help!

Look at what the sentence is conveying.

Acme Bank is providing services including mortgages, home improvement loans, automobile loans, and financial advice. However the list reads as if one of the services they are providing is staying within the metropolitan areas.

Here's an example of a similar error.

Please leave a message including your name, your number, and tell us why you called.

If your name and your number were left out, that sentence would become the following, which clearly does not make sense.

Please leave a message including tell us why you called.

One way to make the sentence make sense is to break up the list in the following way.

Please leave a message including your name and your number, and tell us why you called.

Alternatively the list could be made parallel.

Please leave a message including your name, your number, and the reason why you called.

The list in the question you posted needs to be broken up, because staying within the metropolitan areas is not really part of the list. What's really going on is that Acme bank is providing services and Acme bank is staying within the metropolitan areas.

So the sentence needs to be something like the following. The words I added are in boldface.

By providing such services as mortgages, home improvement loans, automobile loans, and financial advice, and by staying within the metropolitan areas, Acme Bank has become one of the most profitable savings banks in the nation.