Step 1: Understand the problem.
We are asked to identify which type of car showed a continuous increase in production during the period 1989-1994.
Step 2: Analyze the production data for each type of car.
From the table, we have the following production values for each type of car from 1989 to 1994:
- Type A: 8, 20, 16, 17, 21, 6
- Type B: 16, 10, 14, 12, 12, 14
- Type C: 21, 17, 16, 15, 13, 8
- Type D: 4, 6, 10, 16, 20, 31
- Type E: 25, 18, 19, 30, 14, 27
Step 3: Check the trend for each type of car.
- Type A: The production of Type A does not show a continuous increase. It decreases in 1991, 1992, and 1994.
- Type B: The production of Type B does not show a continuous increase. It decreases in 1990 and 1992.
- Type C: The production of Type C does not show a continuous increase. It decreases every year.
- Type D: The production of Type D shows a continuous increase every year from 1989 to 1994.
- Type E: The production of Type E does not show a continuous increase. It decreases in 1991, 1993, and increases again in 1994.
Step 4: Conclusion.
Type D is the only type of car that showed a continuous increase in production during the period 1989-1994.
Final Answer:
The correct option is (D): D.