Hey there! I'm happy to help!
When multiplying numbers with exponents, all you do is add the exponent numbers, so 5^12×5^8=5^20.
A is not equal to this.
B is also not equal to this. B is 25^20.
C is wrong as well. It is 5^5.
This leaves us with D, which does evaluate to 5^20. If you raise a power to a power you multiply the exponent numbers, and 5(4)=20.
The answer is D. (5^5)^4.
Have a wonderful day! :D
