The correct answer is option B
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Explanation of the answer:
By substitution with n = 1 in the given formula we will get
[tex]a_{1}= 5 *( - \frac{1}{8})^{n-1} = 5 *( - \frac{1}{8})^{1-1} =5 *( - \frac{1}{8})^0 = 5 [/tex]
Which is agree with the option B