Final answer:
To find how long the clownfish is, subtract the difference in length between the angelfish and the clownfish from the angelfish's length, which is 3.5 inches. The correct answer is: a).
Step-by-step explanation:
The question involves solving a simple subtraction problem to determine the length of a clownfish based on the length of an angelfish. Given that an angelfish can grow to be 12 inches long and is 8.5 inches longer than a clownfish, we can subtract 8.5 inches from the angelfish's length to find the clownfish's length. Therefore, the calculation would be 12 inches - 8.5 inches, which equals 3.5 inches.
The correct answer is: a) 3.5 inches. This means that the clownfish is 3.5 inches long.