Which expressions are simplified? Pls help!!

Answer:
Only A
Step-by-step explanation:
[tex]b) \: \frac{1}{ {n}^{ - 5} } = {n}^{5} \\ \\ c) \: {n}^{6} \times {n}^{ - 8} = {n}^{ - 2} \\ \\ d) \: {n}^{7} \times {n}^{8} = {n}^{15} \\ \\ e) \: \frac{1}{ {n}^{3} } = {n}^{ - 3} [/tex]