Which command creates a new datatype containing programming languages in SML$?$

it $=$ C $|$ JAVA $|$ SML $|$ SCALA;

datatype language $=$ C $|$ JAVA $|$ SML $|$ SCALA;

language $=$ C $|$ JAVA $|$ SML $|$ SCALA;

String language $=$ C $|$ JAVA $|$ SML $|$ SCALA;