Shadow problems are usually solved with a proportion.
.. oak/(oak's shadow) = joey/(joey's shadow)
.. oak/(12 ft) = (6 ft)/(5 ft)
.. oak = (12 ft)*(6/5) = 14.4 ft . . . . . . . matches selection B
10×8 is that what you mean

so.. that's how many each did, surely you'd know who did the most pizzas.
All I know for sure is that the first one is an inequality