Which statement is correct?
a: a horizontal line has no slope.
b: a vertical line has a slope of zero.
c: a line that rises from left to right has a positive slope.
d: a line that falls from right to left has a negative slope.

A line that rises from left to right has a positive slope

Step-by-step explanation:

Verify each statement

case A) A horizontal line has no slope

The statement is False

Because a horizontal line has a slope equal to zero

case B) A vertical line has a slope of zero

The statement is False

Because a vertical line has a undefined slope

case C) A line that rises from left to right has a positive slope

The statement is True

case D) A line that falls right to left has a negative slope

The statement is False

Because a is a positive slope

6.9

step-by-step explanation:

simple math really

6 1/2 times 0.6 = 3.9

but if you are just doing 6 and not 6 1/2 then the answer is 3.6

the answer is c. 23/3