Organisms of a trophic level that feed on several types of organisms in the lower trophic level constitute the ____. Such interconnected ones are called the _____.

Question

$\begin{array}{1 1} (a)\;\text{Food chain, food web} \\ (b)\; \text{Food web, food chain} \\ (c)\; \text{ Food chain, ecological pyramid} \\ (d)\; \text{Ecological pyramid, food chain} \end{array}$