The correct option is B (an)m
(am)n is a question of repeated exponentiation.
Let's take an example first.
(23)4 represents 4 times multiplication of 23, i.e.,
(23)4
=23×23×23×23
=23+3+3+3
(∵am×an×ap×aq=am+n+p+q)
=212
⇒(23)4=23×4–––––––––––––
By generalizing the above finding, we get:
(am)n=am×n=amn
Similarly, (an)m=an×m=anm=amn
Therefore, amn and (an)m are equal to (am)n.