I need some help solving this problem, thanks for any assistance!

2. Experience indicates that the development time for a photographic printing paper is distributed as X ~ N(30 seconds, 1.21 seconds²). Determine the probability a randomly selected paper's development time is within 2 seconds of the mean.

a) 0.931

b) 0.902

c) 0.912

d) 0.909

e) none of the above

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