Answer:
Pen Drive offers more accessibility
Not every device is equipped with a CD player but every device has a USB port for a pen Drive. Saving on the pen Drive will therefore enable the data to be more accessible.
Pen Drive has more space.
CDs usually have a storage capacity of below a gigabyte whilst pen drives can reach up to 2 terabytes thereby offering exponentially more space to save data.
Safety of Data
CDs are more prone to damage as data could be lost if the CD is scratches. Pen Drives on the other hand are encased in an outer case that protects the data.