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

Input:
Product title: ALIENWARE X51 R2 i7-4790~GTX 760 Ti 2GB DDR5~2TB HDD~8GB RAM
Product description: 8GB Dual Channel DDR3 at 1600Mhz (2x4GB) No Keyboard No Monitor NVIDIA GeForce GTX 760 Ti with 2G GDDR5 WLAN Card DW1550 Driver 2TB (64MB Cache) 7200 RPM SATA 6Gb/s Matte Stealth Black with Dark Chrome Accents Windows 8.1 (64Bit) English Alienware Mouse Is Not Included Slot-Loading Dual Layer DVD Burner (9.5mm) Dell Wireless 1550 (2x2 11ac combo with Bluetooth) US Power Cord English Documentation DAO Warranty Support, Initial Year 1 Year Limited Warranty Dell Hardware Warranty Plus On-Site Service, Initial Year Next Business Day Parts and Labor On-Site Response, Initial Year 4th Generation Intel(R) Core(TM) i7-4790 processor (8MB Cache, up to 4.0GHz) System BOOT for Windows, AW51 Resource DVD windows 8.1 Cyberlink Media Suite Essentials for Windows 8.1 without Media Alienware 330 Watt Power Supply Windows 8.1 DVD OS Recovery(English) Dropbox, Digital Delivery, 20GB for 1 year Promotion
Product feature: Alienware X51 R2, Intel Core i7-4790 (8MB Cache up to 4.0GHz), NVIDIA GeForce GTX 760 Ti 2GB DDR5, 2TB HDD 7200RM SATA ~ 8GB RAM ~ WIFI+Bluetooth, CD/DVD BURNER ~ WINDOWS 8.1 ~ No Keyboard/Mouse
Product brand: Alienware
Target attributes: Monitor Resolution
Answer: attribute: monitor resolution
value: None
source: None