The correct option is A equation
A statement in which the values of two mathematical expressions are equal, which is indicated by the sign '=' is called an equation.
∴4x+y+4=6x+1 is an equation as 4x+y+4 and 6x+1 are algebraic expressions.
Simplifying it by grouping all like terms together, we get
⇒(6x−4x)−y−(1−4)=0
⇒2x−y=3, the simplified form of the equation.