Select the most appropriate option to fill in the blank.
The police were on high alert on account of the ___________ convict who had killed many people.

Correct option is D

The most appropriate option to fill in the blank is Runaway.

• Runaway: someone who has escaped from a place or situation, especially from prison or police custody.
  • Example: The police were on high alert due to the runaway criminal.

Explanation of other options:

• Run after: This means to chase someone or something.
• Walk away: This means to leave or move away from a situation, not fitting in the context of a convict.
• Eloped: This refers to running away secretly, typically with someone to get married, which doesn't fit the context of a convict.

Thus, "runaway" is the most appropriate word.