Concept:
The phrasal verb
\[
\text{break down}
\]
means to stop working, especially for machines and vehicles.
Step 1: Understand the sentence.
The sentence is:
\[
\text{The car _ _ _ _ , while we were going to Vizag.}
\]
Since the subject is a car, the sentence is about a vehicle stopping because of a fault.
Step 2: Choose the correct phrasal verb.
\[
\text{broke down}
\]
means stopped working.
So the sentence becomes:
\[
\text{The car broke down, while we were going to Vizag.}
\]
Step 3: Check other options.
\[
\text{broke in}
\]
means entered by force.
\[
\text{broke out}
\]
means started suddenly, usually war, fire, or disease.
\[
\text{has broken down}
\]
is present perfect, but the sentence refers to a past journey using “were going.”
Step 4: Final answer.
\[
\boxed{\text{broke down}}
\]