Shape of sampling distributions for differences in sample means

A company has offices in two different countries. Employee salaries at both locations are strongly skewed toward the higher salaries.

Every month, the company takes separate random samples of

60

employees from each location for a survey. Each time, they look at the difference in the mean salary sampled from each location

({\bar{x}}_{A} - {\bar{x}}_{B})

What do we know about the shape of the sampling distribution of ${\bar{x}}_{A} - {\bar{x}}_{B}$ ‍, and why?

(Choice A)
It's exactly normal, because both populations are normally distributed.
(Choice B)
It's approximately normal, because both sample sizes are at least $30$ ‍.
(Choice C)
It's skewed, because the populations are skewed, and both sample sizes are at least $30$ ‍.
(Choice D)
The shape cannot be determined since we don't know the shape of either population distribution.

AP®︎/College Statistics