To determine the missing term in the table and the sample size if there were two doors instead of three, let's analyze the problem step-by-step.
1. Identify the Missing Term:
- We are given a table where each key can open one of the three doors. The combinations are listed as follows:
```
Key A: A-1, _, A-3
Key B: B-1, B-2, B-3
Key C: C-1, C-2, C-3
```
- From this table, it is evident that each key is associated with all three possible door combinations. The missing term, corresponding to Key A opening Door 2, should therefore be “A-2”.
2. Determine the Sample Size if There Were Two Doors:
- If there were only two doors (instead of three), each of the three keys would still need to open 2 doors.
- The combinations would then be:
- Key A: A-1, A-2
- Key B: B-1, B-2
- Key C: C-1, C-2
- This results in each key having 2 combinations, and since there are 3 keys, the total number of combinations (sample size) is [tex]\(3 \times 2 = 6\)[/tex].
Based on this detailed analysis, the correct answer is:
A. The missing term is A-2. The sample size would be 6.