Final answer:
The expression (y+3)^4/9 can be written as the 4th root of (y+3) raised to the 4th power or (y+3) to the 4th power and then taking the 9th root, but the provided options do not match this equivalent expression.
Step-by-step explanation:
The expression (y+3)^4/9 is asking to simplify or to find an equivalent form for a rational exponent expression. In mathematics, an exponent of 4/9 means that you would take the 4th root of a number and then raise it to the 4th power, or you could raise the number to the 4th power first and then take the 9th root.
However, none of the provided options A through D are equivalent to the original expression as they appear to be incorrect or incomplete representations.