Jamal simplified the expression startroot 75 x superscript 5 baseline y superscript 8 baseline endroot where x greater-than-or-equal-to 0 and y greater-than-or-equal-to 0.

startroot 75 x superscript 5 baseline y superscript 8 baseline endroot = startroot 25 times 3 times x superscript 4 baseline times x times y superscript 8 baseline endroot = 5 x squared y squared startroot 3 x endroot

which describes the error jamal made?
a. he should have written the square root of y superscript 8 in the answer as y superscript 4, not y squared.
b. he should have written the square root of x superscript 4 in the answer as x, not x squared.
c. he should have written the 5 inside of the radical in the answer.
d. he should have written the 3 outside of the radical in the answer.