Step 1: List minterms (in $WXYZ$).
$4(0100),5(0101),10(1010),11(1011),12(1100),13(1101),14(1110),15(1111)$.
Step 2: Group logically.
- Minterms with $X=1,\,Y=0$ occur for both $W=0$ and $W=1$, independent of $Z$ $\Rightarrow X\overline{Y}$.
- For $W=1$ and $Y=1$ (regardless of $X,Z$) we have 10,11,14,15 $\Rightarrow WY$.
Step 3: Combine.
\[
F = X\overline{Y} + WY,
\]
which already covers all listed minterms with {two} terms and the fewest literals.