multiply (-3 radical 6) (radical 5) give an exact answer please

To multiply \((-3 \sqrt{6})\) by \(\sqrt{5}\), you can follow these steps:

1. Multiply the coefficients: \(-3\).
2. Multiply the square roots: \(\sqrt{6} \cdot \sqrt{5} = \sqrt{30}\).

Putting it all together, you have: \[ (-3 \sqrt{6}) \cdot (\sqrt{5}) = -3 \sqrt{30} \]

The exact answer is \(-3 \sqrt{30}\), which corresponds with option B.