Josh works for MooMoo Milkshakes. The company wants to know what milkshake flavor is the most popular. Today, he surveyed every third female customer on their favorite milkshake flavor. Eighteen customers (out of 59 total) were surveyed, and 6 customers prefer MooChooChocolate, 4 customers prefer VeryStrawberry, and 8 customers prefer BananaBoBanna.

Identify the sample size in the situation above.

A. 6
B. 18
C. 59
D. 4