In a series of 7 archery rounds, Alex's scores were 1, 2, 3, 4, 5, 6, and 7. In his eighth round, he scored fewer than 10 points and his average score for the eight rounds was an integer. Similarly, in his ninth round, he scored fewer than 10 points and his average score for the nine rounds was also an integer. What is the product of the number of points he scored in the eighth and ninth rounds?
12
16
20
24
28
