I think some of the questions and possible responses could have been worded better!
Yes, I used to put DS's outside in the pram to sleep (in good weather) but it was NOT at the bottom of the garden, rather it was just outside the kitchen door.
With co-sleeping, it was something that happened occasionally, so I'm neither for not against. DS1 was born with bi-lateral talipes, so although it was recommended at that time that babies slept on their stomachs, he had a note on his crib in the hospital saying "Please do not put me on my tummy" as that position did not help to get his splinted legs and feet in the best position.
I do get frustrated with the way some surveys or questionnaires are worded. I spent over 6 years designing them for clients to ensure that the data they produced could be considered valid and robust!