Final answer:
The correct answer is a) Blu-ray, which is an optical storage method similar to CDs and DVDs but with higher data capacity due to its use of blue laser technology.
Step-by-step explanation:
CD, DVD, and BLANK discs are examples of optical storage devices that have been used to store digital information. The correct answer to the question is a) Blu-ray, as this type of disc is another form of optical storage. Blu-ray discs use a blue laser to read and write data, which has a shorter wavelength than the red laser used for CDs and DVDs. This allows Blu-ray discs to store information more densely, resulting in a higher capacity for data storage than CDs or DVDs. Blu-ray technology provides significant advancements in optical storage, with the ability to hold a tremendous amount of data on a single disc, such as HD video.