Final answer:
The difference between a quintic trinomial and a quartic trinomial is the degree: a quintic trinomial has a higher degree than a quartic trinomial. The correct answer is A. A quartic polynomial.
Step-by-step explanation:
A quintic trinomial is a type of polynomial that has a degree of 5, meaning the highest power of the variable is 5. A quartic trinomial has a degree of 4, meaning the highest power of the variable is 4.
The difference between these two types of trinomials is the degree: a quintic trinomial has a higher degree than a quartic trinomial.
For example, a quintic trinomial could be x^5 + 2x^4 + 3x^3 + 4x^2 + 5x + 6, while a quartic trinomial could be x^4 + 2x^3 + 3x^2 + 4x + 5.
Therefore, the correct answer is A. A quartic polynomial.