I believe the answer would be B. money market funds.
2/9 = 0.2222 or 0.22
3/9 = 0.3333 or 0.33
4/9 = 0.4444 or 0.44
75,000 divided by 150, is 500, meaning they allow 500 people per acre. 500 times 145 is 72,500, meaning the capacity for a park your size should be 72,500 people.