Instruction: First, identify the target attributes from the provided list. Then, scan the product title, description, feature, and brand to extract the values associated with each target attribute. Finally, create a list of dictionaries, each containing the extracted attribute, its corresponding value, and the source where it was found.

Input:
Product title: Dunkin Donuts K-cups Dark Roast - 24 Kcups for Use in Keurig Coffee Brewers 8.46 Oz
Product description: Once you've had a Dunkin Donuts K-Cups, you will remember it! Dunkin Donuts K-cups have a distinct taste and come in a variety of flavors that allow for a unique and customized experience each and every time. Dunkin Donuts K-Cups allow you to enjoy that same great taste and flavor in the comfort of your own home or office using the Keurig K-Cup brewing system. Dunkin Donuts K-Cups have classic flavors like Original, Dark Roast and Decaf which are joined by Hazlenut and French Vanilla flavors and supercharged with seasonal flavors such as Peppermint Mocha and Pumpkin Spice. Each box contains 12 cups so whether you're enjoying a cup of iced coffee by the pool or a mug of hot chocolate by the fire, Dunkin Donuts K-Cups are sure to add some flavor to your life year round.
Product feature: Dunkin Donuts K-Cups - 2 Boxes of 12 K-Cups ( total 24 units ), Designed for use in Keurig K-Cup brewing machines, In stock ships by next business day, Guaranteed Fresh - Minimum 4 months until use by date, 100 percent Arabica Coffee
Product price: $20.25
Product brand: Dunkin' Donuts
Target attributes: Roast
Answer: attribute: roast
value: dark roast
source: product title
attribute: roast
value: dark
source: product description