To simplify the equation \( 8y + 4 = 6 + 2y + 1y \), let's first combine like terms on the right side.
The right side simplifies as follows:
\[ 2y + 1y = 3y \]
So the equation now looks like this:
\[ 8y + 4 = 6 + 3y \]
Next, we will subtract \( 3y \) from both sides:
\[ 8y - 3y + 4 = 6 \]
This simplifies to:
\[ 5y + 4 = 6 \]
Now, we will subtract 4 from both sides:
\[ 5y = 6 - 4 \]
This gives us:
\[ 5y = 2 \]
Thus, the simplified form of the equation is:
\[ \boxed{5y = 2} \]
So the correct answer is:
5y = 2.