The following table gives the sales of cars manufactured by a company over the years. Answer the following question based on the data in the table.

Number of different types of cars sold (in thousands)

Year	Types
	A	B	C	D
2018	70	80	90	85
2019	50	55	70	75
2020	21	43	78	80
2021	22	40	76	85

The average sales of all four years are the minimum for which type of car?