Which of the following describes the quotient of 3 and -33?

To find the quotient of 3 and -33, we divide 3 by -33:

\[
\frac{3}{-33} = -\frac{1}{11}
\]

Now, let's analyze this result:

- **Undefined**: This does not apply here as we can divide 3 by -33.
- **Rational number**: \(-\frac{1}{11}\) is indeed a rational number because it can be expressed as a fraction of two integers (where the denominator is not zero).
- **Irrational number**: This does not apply as \(-\frac{1}{11}\) is not an irrational number; irrational numbers cannot be expressed as fractions of integers.
- **Integer**: This does not apply as \(-\frac{1}{11}\) is not an integer.

Based on this analysis, the correct answer is:

**B. The quotient is a rational number.**