I want to produce one figure that contains four subfigures and label “a)”, “b)”, "c)", "d)", below and to the left of each subfigure, just like the picture shows.
I searched the Internet, but I only found the method of labeling "a" or "(a)" and did not find the result of "a)" and left justifying.
So, there are two requirements: "a)" and left justifying of four subfigures.