PLEASE HELP ILL GIVE 40 POINTS!! The table shows data collected to represent the functional relationship between the number of people attending a wedding and the cost of the wedding.

A 2-column table with 5 rows. Column 1 is labeled People, x with entries 5, 10, 15, 20, 25. Column 2 is labeled Cost (dollars), y with entries 445, 890, 1,335, 1,780, 2,225.

What is the domain of the function represented by the table?

A: all real numbers
B: x greater-than-or-equal-to 0
C: all integers greater than or equal to zero
D: {5, 10, 15, 20, 25}