Answer: Top right graph.
Explanation:
The function ⌊x⌋ rounds the value x to the lower whole number.
for example:
⌊1.5⌋ = 1
⌊1.923⌋ = 1
⌊2.0⌋ = 2
then, the graph of ⌊x⌋ will be a black dot in the each whole number, and a horizontal segment to the right that ends with a white dot in the next whole number. Right above the white dot, we have another black dot, and it repeats.
if we have ⌊x⌋ + 2, we move te previous graph 2 units upwards, then the correct option is the top right graph.
You can check some points if you like:
f(0) = ⌊0⌋ + 2 = 2
f(0.5) = ⌊0.5⌋ + 2 = 2
f(1) = ⌊1⌋ + 2 = 3
So in x = 0 we have a black dot in y = 2, and in x = 1 we have a white dot in y = 2 and a black dot in y = 3.