Q2

The following proof aims to establish that $-4=0$.

Let $a=-4$.

$\Rightarrow a^2=16$ and $4a+4=-12$ (Line 1)

$\Rightarrow a^2+4a+4=4$ (Line 2)

$\Rightarrow (a+2)^2=2^2$ (Line 3)

$\Rightarrow a+2=2$ (Line 4)

$\Rightarrow a=0$

At which line is the implication incorrect?

A. Line 1
B. Line 2
C. Line 3
D. Line 4