Study the given table and answer the question that follows.
The table shows the production of different varieties of rice (in quintals) from 2018–2021.
| Variety | Year | |||
| 2018 | 2019 | 2020 | 2021 | |
| A | 20 | 35 | 55 | 67 |
| B | 45 | 45 | 89 | 87 |
| C | 67 | 89 | 67 | 98 |
| D | 34 | 65 | 76 | 78 |
In which year was rice of variety C produced the maximum?