Answer:
Option B -

Explanation:
Given : Fidel has a rare coin worth $550. Each decade, the coin's value increases by 10%.
To find : Which expression gives the coin's value, 6 decades from now?
Solution :
The given situation represents the exponential function,

where, a is the initial value i.e. a=$550
r is the increased rate r=10%
n is the time i.e. n=6
Substitute the value in the formula,


Therefore, option B is correct.