Which of the following rules are common ground between the two languages?

There are many syntax differences between SAP HANA SQLScript and Open SQL.

Which of the following rules are common ground between the two languages? There are 2 correct answers to this question.
A . Host variables are escaped with an at symbol (@)
B . Statements are ended with a period (.)
C . Comments can be marked by an asterisk (*) at position 1
D . Key words can be upper-case or lower-case

Answer: C,D