In successive experiments while measuring the period of oscillation of a simple pendulum. The readings turn out to be `2.63 s, 2.56 s, 2.42 s, 2.71s and 2.80 s.` Calculate the mean absolute error.
Options:
(a) `0.11s`
(b) `0.42 s`
(c) `0.92 s`
(d) `0.10 s`