Which code segment should you insert at line CM06?

###BeginCaseStudy###
Case Study: 2
Windows Store app
Background
You are developing a Windows Store app by using HTML5, JavaScript, and CSS3. The app
will be used to access details about products that your company sells.
Business Requirements

The app must do all of the following:
• Be available to customers in many different countries.
• Display a list of product categories.
• Display the products for a selected category.
• Display details of a selected product.
• Display images of each product one at a time in a vertical presentation.
• Provide a link to an about section in the Settings pane.
• Update product data on a daily basis.
• Allow the user to view the last selected product while the app is offline.
• Be deployed in the Windows Store.
Technical Requirements
General
• When the user restarts the app, the app must start in the state it was in when it was last
used.
• App settings controls must be 346 pixels wide.
• The app must optimize bandwidth use and performance.
Security
• The app must use an enterprise certificate.
• The user must provide valid credentials to access the app.
• After user authentication, the app must use stored credentials.
• User accounts will be validated against a pre-existing enterprise service.
App Architecture
• Service calls must be separated from the user interface.
• The app must follow the MVC design pattern.
• Service classes can be written in C++, C#, VB, or JavaScript.
• The app must communicate with pre-existing enterprise services.
Application Structure
Relevant portions of the app files are shown below. (Line numbers in the code segments are
included for reference only and include a two-character prefix that denotes the specific file to
which they belong.)

###EndCaseStudy###
You need to implement the saveCredentials method.
Which code segment should you insert at line CM06?

A.
Option A

B.
Option B

C.
Option C

D.
Option D