For the unit rate, you are looking for how much one unit of something costs. Looking at the table, you'll see that 3 bottles of fragrance A costs $78. What you want to figure out is how much one bottle costs.
You can do this by taking the price and dividing it by how many there are.
78 ÷ 3 = $26
156 ÷ 6 = $26
234 ÷ 9 = $26
You can see that each bottle of fragrance A costs $26.
Now looking at the graph, you'll see that the line only lines up perfectly at 2 points: (1, 24) and (2, 48). This tells us that for each bottle of fragrance B, it costs $24.
Comparing the two, fragrance A will have the greatest unit rate.