22 points anwser ASAP please Which of the following would graph a line with a slope of zero?

a
y = 2x - 3
b
y = 3
c
x = 3
d
3x +4y = 0

Apatient is to be given 35 milligrams of demerol every 4 hours. you have demerol 50 milligrams/milliliter in stock. how many milliliters should be given per dose?

Find the ratios of the corresponding sides

Set $r$ is a set of rectangles such that (1) only the grid points shown here are used as vertices, (2) all sides are vertical or horizontal and (3) no two rectangles in the set are congruent. if $r$ contains the maximum possible number of rectangles given these conditions, what fraction of the rectangles in set $r$ are squares? express your answer as a common fraction.