Answer:
d. bar graph
Step-by-step explanation:
A bar graph (e.g bar chart or histogram) can be used to illustrate or compare the variation of a variable with respect to other variables. It could be in the form of vertical or horizontal graph.
To visually show the populations of 10 cities in Texas, the best tool to use is the bar graph. This tool would make it possible to compare even the populations of males and females in each city (bar chart). And the details can be easily obtained from the plotted graph.