Target Audience Research + Questionnaire.

I've been looking into previous horror films and who they have been aimed at to help me figure out who I want my target audience to be.  I found that a horror films target audience is generally those in the age group 15-25. In the previous post;
 http://www.blogger.com/blogger.g?blogID=4211012246451120327#editor/target=post;postID=6851651350707642593;onPublishedMenu=posts;onClosedMenu=posts;postNum=18;src=postname

 I Looked at the BBFC's classification. From this I looked at the main points for the certificates 15 and 18, I found that there wasn't much difference between them other an 18 certificate film would contain more of the content then a 15. I am aware that my trailer for my film will fall under one of these certificates. However, until I am more aware of the content I'm not sure which one. 
I've decided to produce a questionnaire which I will present to a range of people ageing from 15 to 25+. I think a questionnaire will help me to confirm my target audience and what they want from a horror film. I have concluded five questions will I will ask around 20 people to do, shown below which I think will give me the best possible indication to whom I should aim my teaser trailer at.

1. How old are you?

-15 - 17
- 18 - 20
- 21 - 25
- 25+

2. How often do you watch a horror film? 

- All the time
- Sometimes
- Once in a while
- Never

3. What type of horror film are you most inclined to watch?

- Gore/ Violent
- Supernatural 
- Psychological
- Thriller

4. For you, What is the most important part of a teaser trailer?

- Violence
- Characters shown
- Hardly any plot revealed
- A lot of the plot revealed
- Suspense/ Apprehension

5. For you, What makes a teaser trailer most successful?

- The plot 
- Depth of knowledge about the characters
- Camera Shots
- Music/ Sound
- Lighting