Instruction: Extract the value of the target attribute from the given product information and output it along with the corresponding source.

Input:
Product title: Acer DT.VFFAA.003;VM2611G-UI3324X Desktop
Product description: Acer VM2611G-UI3324X Intel Core i3-3240 3.4GHz/ 4GB DDR3/ 500GB HDD/ Windows 7 Pro & Windows 8 Pro Desktop PC (Black)
Product feature: Intel Core i3-3240 Processor 3.4 GHz, 4GB DDR3, 500 GB 7200 rpm Hard Drive, Windows 7 Professional
Product brand: Acer
Target attributes: Monitor Size
Answer: attribute: monitor size
value: None
source: None