Easiest way:
Look at A and C. To get from A to C you need 6 steps to the right and 2 steps upwards.
Slope means (in layman's terms) that how many steps you take upwards when you take 1 step to the right.
In your case you take 2/6 steps, because it would take you 6 steps to the right to go 2 steps upwards.
A slope of 4 would mean that 1 step to the right is followed by 4 steps upwards. A slope of -5 means 1 step to the right, 5 steps downwards.
To get from A to E you need 9 steps to the right and 3 steps upwards. This means a 3/9 slope. The simplest form of it is 1/3.
1/3 slope means that for every 3 steps to the right you take 1 step upwards.
I hope this was understandable, this is how they taught me this in 5th grade more than a decade ago.
The answer is : multiply 5
The independent variable is that whose values do not take into account the values of other variables. That is the time in hours for this item. Then, for the dependent variable, the answer would be the cost of renting. The value of the dependent variable is based on the changes done in the values of the independent variable.
Sec theta = 1/cos theta = 1/0.5 = 2
Option D is the correct answer.