The table shows the amount of protein in two types of legumes and the cost of each. Based on the table, what is the ratio of the cost per gram of protein in chickpeas to the cost per gram of protein in black beans?
| Food | Protein | Cost |
|---|---|---|
| Chickpeas | 40 grams | $1.60 |
| Black beans | 50 grams | $1.50 |
3 : 4
4 : 3
1 : 1
16 : 15
