Here are the graphs .....
First one : https://www.desmos.com/calculator/mw7uveztel
Second one : The top right graph is correct......the function is constant at y = 3 from -infinity to x = 1
When x > 1, y = x ...... so the points (2,2), (3,3) , (4,4) etc. are on the graph
Third one : https://www.desmos.com/calculator/ze9my3umlo
Last one : This one is probably a little strange to you......it's known as "the ceiling function" graph
In other words, the "ceiling" of a value x is the least integer that is greater than or equal to x
So...ceiling of 1.5 = 2
ceiling of -3.4 = -3
ceiling of 2 = 2
These graphs always have a "hole" on the left end of each segment.....so we can eliminate the graphs at the bottom
To see which of the top graphs are correct......let's pick an x value in the given interval, say, 1.5, and put it into the function .....so......1.5 + 1 = 2.5.....and the "ceiling" of this = 3
So (1.5, 3) should be on the graph
Also if we picked 1 then 1 + 1 = 2 and the ceiling of 2 = 2
So (1, 2) should also be on the graph
Looks like the graph on the top right is correct !!!
Here's the graph : https://www.desmos.com/calculator/ffxtehmg8g