Final answer:
The correct expression for raising t to the 8th power and then dividing u by the result is written as u ÷ t^8 or u/t^8 in fractional form. The given options do not accurately represent the operation described.
Step-by-step explanation:
The student is asked to write an expression that first involves raising the variable t to the 8th power, and then dividing the variable u by this result. The correct expression for this operation is u ÷ t^8, which translates to 'divide u by t raised to the 8th power.'
It is important to note that, according to the rules for division of exponentials, you do not subtract exponents when dividing with different bases. Therefore, the correct option that represents this expression is none of the given choices A, B, C, or D; the proper notation should be u ÷ t^8 or written as u/t^8 in fractional form.