Survey

Can someone help me please as soon as possible. 

All the other section of the radio button work properly meaning you can only select one radio button per each question but the second slide question  "I can format text (e.g. size, colour, bold)" and forth slide question "I can recognise some other social media sites e.g. Instagram, Twitter, Pinterest and You Tube"

Rather than the radio button worked just like the others, its selection multiple which is not what I want. 

Can someone please take it look please or maybe try and fix one one of the slide with explanation of what I did wrong. 

Thank You. 

Much Appreciated.