Answer:
d, 0.43 championships per year
Step-by-step explanation:
First, lets find out how many championships per year. You can get this by doing 3÷7. The answer will be 0.42857142857. Of course, for this problem, we should round to 0.43. This eliminates option "b" and "c". Now, the two true options are "a" and "d", but we can eliminate "a" because the question asks for a unit rate. That means per year, not per 2 years. So, the answer is "d", or 0.43 championships per year.
