What must be true about the slopes of two perpendicular lines, neither of which is vertical?

(1 point)
Responses

The slopes are equal.
The slopes are equal.

The slopes have product 1.
The slopes have product 1.

The slopes have product negative 1.
The slopes have product Image with alt text: negative 1 .

One of the slopes must be 0.

The slopes have product negative 1.