The Advanced Editor $-$ M Code

The Power Query editor allows us to interact with our data visually. Still, the actual recording of steps takes place in a language called M$,$ which we can access using the Advanced Query Editor.

Which of the following is NOT true about M$?$

Comments can be added using $//$ at the beginning of a line.

$M$ is a functional language, meaning that each line returns a new answer or table.

Generally speaking, each functional line of M code within the let statement is followed by a comma.

The In statement defines the source of the data.