An increase in promotional budgets have:
a. increasing returns over time.
b. level returns over time.
c. decreasing returns over time.
d. decreasing then increasing returns over time.
e. increasing then decreasing returns over time.
a. increasing returns over time.
b. level returns over time.
c. decreasing returns over time.
d. decreasing then increasing returns over time.
e. increasing then decreasing returns over time.