The correct formula for the surface area (S.A.) of a rectangular prism is:
\[ \text{S.A.} = 2(l \cdot w) + 2(w \cdot h) + 2(l \cdot h) \]
or, equivalently,
\[ \text{S.A.} = 2(lw + lh + wh) \]
Where:
- \( l \) = length
- \( w \) = width
- \( h \) = height
So the response that correctly represents this is:
S.A. = 2(w ⋅ l) + 2(w ⋅ h) + 2(l ⋅ h).