Is the Citroen C4 Cactus safe?

Please advise if a used Citroen C4 Cactus is a good buy, given its 4-star Euro NCAP rating. I think this is due to the absence of autonomous emergency braking (AEB) when tested in 2014. Should this deter...

Looking to buy the safest car for a young driver - which have autonomous breaking?

I'm looking to buy the safest car for a young and newly qualified driver. Cars with autonomous breaking would appeal ideal - which (if any) would you recommend? Cost is important.