MacBook Air, Mid2013, MacOS 10.9.2; I tried to erase the HD of my Mac; Apple Support suggested restarting the computer pressing cmd R, then select "Utility Disk", then Mac HD, choose "Erase", the option "Security Options" should be available, it was not

MacBook Air, Mid2013, MacOS 10.9.2

I tried to erase the HD of my Mac; Apple Support suggested to restart the computer pressing cmd + R, then select "Utility Disk", then Mac HD, and choose "Erase", the option "Security Options" should be available, but it was not

I was able to erase the disk and reinstall the OS but not to choose the option to overwrite the disk, as the official Apple Support said previously.

I called again them, this time I was said that with an SSD disk the security option (overwrite the disk) is not available, and that is it, no way out; and they added very kindly that if I sell my Mac, the buyer could bring it to a Tech Center and they could eventually recover the data on it, even though this may be expensive

Is there anyone that has any suggestion to protect the data before selling a Mac; the guys at Apple Official Support did not seem very concerned about this