A student used a measure of spread to conclude that the movie ticket prices $($in dollars$)$ in

set A were more spread out than those in set B$.$ Which measure of spread did he use?

Set A: $10,11,11,13,15$

Set B: $10,11,13,13,15$

a$.$ The range.

b$.$ The IQR.

c$.$ The standard deviation.

d$.$ None of the above.

e$.$ All of the above.