Answer:
The product of 6 and a number
Explanation:
There isn't any "real" mathematics needed to find the answer, just common background knowledge:
6x = 6 times x,
and product is referencing multiplication
(Since quotient is for division, difference for subtraction, and sum for addition)
considering we need to represent an expression which uses multiplication in words, the correct answer is:
O the product of 6 and a number