Select the most appropriate option to fill in the blank.

I was not even ________________ that my friend was ill.

aware

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

The word aware means to know or to be conscious of something. In this case, the sentence is saying that I was not even aware that my friend was ill. This means that I did not know that my friend was ill.

The other options are not correct.

• Alert means to be watchful or to be on the lookout for something. It does not make sense in this context because I was not being watchful or on the lookout for my friend's illness.
• Brave means to be courageous or to be fearless. It does not make sense in this context because I was not being courageous or fearless.
• Cruel means to be mean or to be unkind. It does not make sense in this context because I was not being mean or unkind.