Concept:Identify the grammatical error in the sentence, specifically the incorrect use of the preposition 'about' before the infinitive 'to visit'.
Explanation:The phrase 'is about to' indicates an imminent action that is about to happen soon.
However, the intended meaning is that his dream now is the desire or aspiration to visit the moon.
Therefore, the correct phrase should be 'his dream now is to visit the moon'.
The word 'about' in part c) is redundant and creates a grammatical error.
The corrected sentence: "Having read a number of stories about space travel, his dream now is to visit the moon."
Hence, the error is in part c).
Answer:C