Školjka

%V0 Let $P$ be a convex polygon. Prove that there exists a convex hexagon that is contained in $P$ and whose area is at least $\frac34$ of the area of the polygon $P$. Alternative version. Let $P$ be a convex polygon with $n\geq 6$ vertices. Prove that there exists a convex hexagon with a) vertices on the sides of the polygon (or) b) vertices among the vertices of the polygon such that the area of the hexagon is at least $\frac{3}{4}$ of the area of the polygon. I couldn't solve this one, partially because I'm not quite sure of the statements' meaning (a) or (b) :) Obviously if a) is true then so is b).