Question

2.

Answer 1

Answer: Choice C) Multiplication property of inequality

The rule basically says that if you start with a < b and you multiply both sides by some positive number c, then a*c < b*c. The sign doesn't flip if you multiply both sides by a positive number.
The sign will flip if c is negative. So we'll go from a < b to a*c > b*c if c is negative.

Example 1:
1 < 5
-2 > -10 ... multiplied both sides by -2; sign flips

Example 2: 
3 < 7
9 < 21 ... multiplied both sides by 3; sign does not flip

Similar rules apply to a > b, $a \le b$ and $a \ge b$