Complement of an element $x$ is said to be $y$, iff Lowest Upper bound of $x$ and $y$ is the upper bound of lattice and Greatest Lower bound is the lower bound of lattice.
In the above lattice, Upper bound $ = h$ and Lower bound $= a$. So, two elements are complement of each other only if their LUB and GLB are $h$ and $a$ respectively.
$LUB(c,f) = h$ and $GLB(c,f) = a$. So, $a$ and $f$ are complement of each other.
$LUB(e,f) = f \ne h$ and $GLB(e,f) = e \ne a$.
$LUB(d,g) = h$ and $GLB(d,g) = c \ne a$.
Hence, Option (B) and Option (C) are not correct.