Instruction: Parse the product information to locate the target attribute, and then provide the extracted value of the target attribute and its source in the output, specifying None if the attribute is not present.

Input:
Product title: Toshiba Satellite M45-S269 15.4" Laptop (Intel Pentium M Processor 740 (Centrino), 512 MB RAM, 100 GB Hard Drive, DVD SuperMulti Drive)
Product description: Move up to Intel Centrino Mobile Technology for greater processing power, extended battery life, and high speed wireless connectivity! The advanced SATA 100GB HDD and DVD burner ensure years of growth and unlimited storage. Intel Graphics Media Accelerator 900 with 8MB-128MB dynamically allocated graphics memory 3-USB (2.0) ports, i.LINK IEEE 1394 port, TV-out (S-Video), 10/100 Ethernet port, V.92 modem port, headphone jack, external microphone jack (monaural), RGB monitor port Dimensions (WxDxH Front/H Rear) - 14.2 (360.0mm) x 10.6 (268.5mm) x 1.14 (29.0mm)[F]/1.43 (36.2mm)[R] without feet Manufacturer's 1 Year Standard Limited Warranty
Product brand: Toshiba
Target attributes: Refresh Rate
Answer: attribute: refresh rate
value: None
source: None