Explanation:

To solve this series, we need to identify the pattern and fill in the missing parts. Let's analyze the given series step by step.

Step 1:
The series starts with "ccc".

Step 2:
After "ccc", we have "bb" followed by three underscores.

Step 3:
Next, we have "aa" followed by four underscores.

Step 4:
Then, we have "cc" followed by two underscores.

Step 5:
After that, we have "bbb" followed by two underscores.

Step 6:
Finally, we have "aa" followed by one underscore and "c" at the end.

Pattern:
From the above analysis, we can observe the following pattern in the series:
- The number of underscores between the characters increases by one with each step.
- The characters in each step alternate between "c" and "b" or "a".

Completing the Series:
To complete the series, we need to apply the pattern we identified.

Step 1:
The pattern starts with "ccc".

Step 2:
Next step is "bb" followed by three underscores.
So, the next part is "bbba".

Step 3:
After "bbba", we need to add "aa" followed by four underscores.
So, the next part is "bbbaa____".

Step 4:
Next, we need to add "cc" followed by two underscores.
So, the next part is "bbbaa____cc____".

Step 5:
After "bbbaa____cc____", we need to add "bbb" followed by two underscores.
So, the next part is "bbbaa____cc____bbbaa____".

Step 6:
Finally, we need to add "aa" followed by one underscore and "c" at the end.
So, the complete series is "bbbaa____cc____bbbaa____c".

Conclusion:
By applying the identified pattern, we can see that the correct option to complete the series is option B - "baca".