What was the importance of the Turing machine to today's computers?

What was the importance of the Turing machine to today's computers?
 
  a. It described a system that was a precursor to today's notebook computer.
  b. It was the first electronic calculator and a precursor to the computer.
  c. It was the first computer to have a monitor.
  d. It described a process to read, write, and erase symbols on a tape and was the precursor to today's RAM.

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According to the text, which of the following is NOT typically one of the important features when selecting a digital camera?
 
  A) Lenses
  B) Storage type
  C) Weight
  D) Resolution