Select the most appropriate option to fill in the blank.

My friend is not ______ for this complicated assignment.

suitable

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

The sentence is saying that my friend is not the right person for this complicated assignment. The word "suitable" means appropriate or fitting for a particular purpose. In this case, my friend is not appropriate or fitting for the complicated assignment.

The other options are not as appropriate.

• Worthy means deserving of something. It does not make sense in the context of the sentence, because my friend is not deserving of the complicated assignment.
• Comfortable means feeling relaxed and at ease. It does not make sense in the context of the sentence, because my friend is not comfortable with the complicated assignment.
• Entitled means having a right to something. It does not make sense in the context of the sentence, because my friend does not have a right to the complicated assignment.