which of the following is not an expression?

[tex]\huge \bf༆ Answer ༄[/tex]
The Correct choice among them is ~ B
[tex] \large \boxed{3x + 4 = 7}[/tex]
because it's a equation !
Answer:
3x + 4 = 7
Step-by-step explanation:
Equations contain an equal sign, but expressions only contain numbers and variables.