The answer Is option B because it best paraphrases the article.
Duo lingo works pretty good !
An infinitive is the word "to" plus a verb so if you see that in a sentence its probably an.infinitive (I'll give an example below)
Ex: Renee suprised her sister to scare her.
-The infinitive would be "to scare" because it could be mistaken as a verb but the actual verb is "surprised"
Hope that helped!
Answer:
a)I wonder what we are having for dinner tonight, Sam mentioned.
b) please do not shout your answers , Mrs.Cox demanded.
