A 2-column table with 8 rows. The first column is labeled x with entries negative 6, negative 5, negative 4, negative 3, negative 2, negative 1, 0, 1. The second column is labeled f of x with entries 34, 3, negative 10, negative 11, negative 6, negative 1, negative 2, negative 15.

Using only the values given in the table for the function, f(x), what is the interval of x-values over which the function is increasing?
a) (–6, –3)
b) (–3, –1)
c) (–3, 0)
d) (–6, –5)