The following questions are based on letter series in which some letters are missing. The missing letters are given in a proper sequence as one of the alternatives among the given four alternatives under each question
ba--baabba-b

Options

A. aba
B. bab
C. caa
D. baa

Explanation

To solve the problem of finding the missing letters in the series "ba--baabba-b", we will analyze the given sequence step by step.

### Step-by-Step Solution:

1. **Identify the Given Series**:
The series provided is: B, A, __, __, B, A, A, B, B, A, __, B.

2. **Analyze the Pattern**:
We can observe the letters in pairs. Let's break it down:
- The first part is B, A.
- The next two positions are missing.
- Then we have B, A, A, B, B, A.
- Finally, there is one more missing letter before the last B.

3. **Fill in the Missing Letters**:
- Starting with the first two missing letters:
After B, A, we can see that the next letters are B, A, A.
The pattern seems to suggest that after B, A, we should have A (to maintain the sequence of letters).
- Therefore, the first missing letter is A.
- For the second missing letter, we again see that after A, we have B, so we can conclude that the second missing letter should also be A.
- Now we have: B, A, A, A, B, A, A, B, B, A, __, B.
- The next missing letter follows the pattern of A, B, A, A, B.
- After two A's, we have a B. Hence, the next missing letter should be B.

4. **Final Sequence**:
Putting it all together, we have:
B, A, A, A, B, A, A, B, B, A, B, B.

5. **Identify the Missing Letters**:
The missing letters in the sequence are A, A, B.

### Conclusion:
The complete sequence with missing letters filled in is B, A, A, A, B, A, A, B, B, A, B. The missing letters are A, A, B.

### Answer:
The correct option for the missing letters is **ABA**.