Question

what does the o - horizon consist of?
weathered rock and organic material
broken down bedrock
clay
humus and leaf - litter

Explanation:

The O - horizon is the top layer of soil and consists mainly of humus and leaf - litter. It is rich in organic matter. Weathered rock and organic material is more characteristic of deeper horizons in some cases. Broken down bedrock is part of lower horizons like the C - horizon. Clay is a component of soil but not the main component of the O - horizon.

Answer:

humus and leaf - litter