I got two wrong however I disagree with one
Comparing an ancestor’s marriage certificate to his baptism certificate and to a census entry from immediately before the wedding, you discover that he used a completely different first name when he married. Was the marriage…
In England and Wales a person's name is the name they decide to be known as.
If a person changed their name between baptism or even the census schedule (which could have been filled in by someone who did not know what name he or she wished to be known as) and the marriage then the marriage was valid.
The question is clearly wrong.

It should have been
"If a person used a false name on marriage..."
Cheers
Guy