Which is the recommended method to transfer a wordpress site to wordpress Multisite?

I want to create a wordpress site on my local server and then trasfer it into another server that runs a wordpress multisite installation.

Which way is safer to follow:

a) install a wordpress single installation in my local server and after development export it and import it to the wordpress MU which already has a blank site and the theme and plugins installed

b) install a wordpress MU installation in my local server and after development export the specific site and import it to wordpress MU which already has a blank site and the theme and plugins installed

Is any of the above recommended or both are the same?

P.S: the requirements say that WP version has to be 3.6.1

Using the WordPress XML export doesn’t work in every case. Especially if you have to deal with plugins.

I had the best results if I first installed the theme and all plugins in the network, created a new site, activated theme and plugins (in case they create data base tables) and then import the WordPress XML.

For NextGenGallery it didn’t work, though. I had to copy all images and the data base tables manually. The path for each image needs to be mended with search and replace, since in the network installation you’ll use blogs.dir/<number>/ for uploads.