\"\"

\

 Given equation is \"\" 

\

\"\"         (Add 3y to each side)

\

\"\"          (Apply commutative property: \"\")

\

\"\"                   (Apply additive inverse property: \"\")

\

\"\"                          (Apply additive identity property: \"\")

\

\"\"

\

\"\"           (Subtract 18 from each side) \ \

\

\"\"                      (Apply additive inverse property: \"\")

\

\"\"                           (Apply additive identity property: \"\")

\

\"\"

\

\"\"                      (Divide each side by 3)

\

\"\"                          (Cancel common terms)

\

\"\"                        (Simplify)

\

\"\"                             (Divide:  \"\"\"\") \ \

\

\"\".

\

\"\"

\

The option "C" is correct.