In this lesson I think you have to use:
.text((d)=>d[0] + ', ' + d[1])
.attr("x", (d) => d[0]+5)
.attr("y", (d) => h - d[1])
I don’t think I understand the purpose of the line:
.text((d)=>d[0] + ', ' + d[1])
before the next two lines. The objective is to create an x and y point for a series of labels and since the second two lines do this I can’t work out the point of the first.